Novel method for the production of 18F-labeled active esters and their application exemplified by the preparation of a PSMA-specific PET-tracer

Abstract

Novel efficient, time-saving and reliable radiofluorination procedures for the production of .sup.18F-labelled active esters via nucleophilic substitution of the corresponding onium precursors with .sup.18F.sup.− are described. The active ester including [.sup.18F]F-Py-TFP and [.sup.18F]TFB produced by one of these methods was used to prepare PSMA-specific PET tracers such as [.sup.18F]DCFPyL. The key advantages of these inventive methods are efficiency, short time of preparation and excellent amenability to automation. A pharmaceutical composition containing at least one PSMA-specific PET tracers prepared by the inventive method is useful for positron emission tomography (PET) imaging, especially imaging prostate tumor.

Claims

1. A compound of formula (II) ##STR00109## wherein, E represents a covalent bond or ##STR00110## ##STR00111##  wherein n is an integer selected from 0 to 10; n.sub.1 is an integer selected from 0 to 10; n.sub.2 is an integer selected from 0 to 10; m is an integer selected from 1 to 18; p is an integer selected from 0 to 10; q is an integer selected from 1 to 18; X, Y, W, and Z represent independently of each other —CH.sub.2—, —CH—, —NH— or —N—; represents a single or double bond; and diastereomers, enantiomers, hydrates, and salts thereof.

2. A compound of formula (II) ##STR00112## wherein, E represents a covalent bond or ##STR00113## wherein n is an integer selected from 0 to 10; m is an integer selected from 1 to 18; X, Y, W, and Z represent independently of each other —CH.sub.2—, —CH—, —NH— or —N—; represents a single or double bond; and diastereomers, enantiomers, hydrates, and salts thereof.

3. A compound according to claim 1, wherein said compound is a direct precursor of the compound of formula (I) ##STR00114## wherein A, B, C, and D represent independently of each other C—H, C—F, C—Cl, or N; and not more than two of A, B, C, and D represent N; E represents a covalent bond or ##STR00115## ##STR00116##  wherein R.sup.1 represents C.sub.1-C.sub.3 alkyl, C.sub.1-C.sub.3 alkoxy, C.sub.1-C.sub.3 haloalkyl, C.sub.1-C.sub.3 thioalkyl, perfluoralkyl, C.sub.1-C.sub.3 haloalkoxy, C.sub.1-C.sub.4 alkylcarbonyl, C.sub.1-C.sub.4 alkyloxycarbonyl, C.sub.1-C.sub.4 alkylcarboxy, aryloxy, alkylaryl, aryl, arylcarboxy, halogen, preferably Cl or Br, trifluoromethyl, cyano or nitro; n is an integer selected from 0 to 10; n.sub.1 is an integer selected from 0 to 10; n.sub.2 is an integer selected from 0 to 10; m is an integer selected from 1 to 18; p is an integer selected from 0 to 10; q is an integer selected from 1 to 18; X, Y, W, and Z represent independently of each other —CH.sub.2—, —CH—, —NH—, or —N; represents a single or double bond; and diastereomers, enantiomers, hydrates, and salts thereof.

4. The compound according to claim 3, wherein the compound is a direct precursor of the compound of formula (I) of claim 3, ##STR00117## wherein A, B, C, and D represent independently of each other C—H, C—F or N; and not more than two of A, B, C, and D represent N; E represents a covalent bond or ##STR00118##  wherein R.sup.1 represents C.sub.1-C.sub.3 alkyl, C.sub.1-C.sub.3 alkoxy, C.sub.1-C.sub.3 haloalkyl, C.sub.1-C.sub.3 haloalkoxy, C.sub.2-C.sub.4 alkylcarbonyl, C.sub.2-C.sub.4 alkyloxycarbonyl, C.sub.2-C.sub.4 alkylcarboxy, aryloxy, arylcarboxy, cyano, or nitro; n is an integer selected from 0 to 10; m is an integer selected from 1 to 18; X, Y, W, and Z represent independently of each other —CH.sub.2—, —CH—, —NH— or —N—; represents a single or double bond; and diastereomers, enantiomers, hydrates, and salts thereof.

5. The compound according to claim 1, wherein either of n or n.sub.1 or n.sub.2 is an integer selected from 1 to 4.

6. The compound according to claim 1, wherein either of n or n.sub.1 or n.sub.2 is an integer selected from 1 or 2.

7. The compound according to claim 1, wherein either of m is an integer selected from 1 to 10.

8. The compound according to claim 1, wherein either of m is an integer selected from 1 to 4.

9. The compound according to claim 1, wherein either of p is an integer selected from 0 to 6.

10. The compound according to claim 1, wherein either of p is an integer selected from 0, 2 to 4.

11. The compound according to claim 1, wherein either of q is an integer selected from 1 to 10.

12. The compound according to claim 1, wherein either of q is an integer selected from 1 to 3.

13. A compound according to claim 1 selected from the group comprising compounds 2a-2p: ##STR00119##

14. The compound according to claim 1, wherein the salt is selected from the group comprising acetate, trifluoroacetate, tosylate, mesylate, triflate, chloride, bromide, iodide, sulfate, hydrosulfate, nitrate, perchlorate, lithium, sodium, potassium, cesium, trialkylaryl-, tetraaryl-, tri- and tetralkylammonium salts.

15. A compound according to claim 3, wherein the direct precursor of the compound of formula (I) is suitable of being coupled to a compound of formula (III), optionally in an anhydrous protic solvent, preferably in a C.sub.2-C.sub.5 alcohol, preferably ethanol wherein formula (III) is ##STR00120## wherein A, B, C, D and R.sup.1 have the meanings as defined, and OL represents a leaving group, optionally wherein the residue L of the leaving group OL in formula (III) represents preferably: ##STR00121## and wherein R.sup.5 is selected from methyl, ethyl, or n-propyl, further optionally wherein the compound (III) is selected from the group comprising: ##STR00122##

16. A method of preparing a compound (III) ##STR00123## wherein A, B, C, D and R.sup.1 have the meanings as defined, and OL represents a leaving group, optionally wherein the residue L of the leaving group OL in formula (III) represents preferably: ##STR00124## and wherein R.sup.5 is selected from methyl, ethyl or n-propyl, further optionally wherein the compound (III) is selected from the group comprising: ##STR00125## comprising the following steps (A1)-(A8): (A1) providing a solution of a compound of the formula (IV) in at least one polar protic solvent or in a solvent mixture containing a polar protic solvent, ##STR00126## wherein A, B, C, D, OL and R.sup.1 have the same meanings as defined; X represents NR.sup.2.sub.3, IR.sup.3, SR.sup.3.sub.2; Y represents Br, I, BF.sub.4, O.sub.2CCF.sub.3, OSO.sub.2CF.sub.3, ClO.sub.4, NO.sub.2, OSO.sub.2C.sub.6H.sub.4CH.sub.3, OSO.sub.2CH.sub.3; R.sup.2 represents C.sub.1-C.sub.4 alkyl; and R.sup.3 represents aryl; (A2) providing an aqueous solution of [.sup.18F]fluoride; (A3) loading the aqueous solution of [.sup.18F]fluoride onto an anion exchange resin; (A4) washing the anion exchange resin with a polar protic solvent or with a polar aprotic solvent; (A5) flushing of the solvent with air or inert gas flow; (A6) eluting of [.sup.18F]fluoride with the solution of the compound of formula (IV) provided in step (A1), preferably in EtOH and diluting of the resulting solution with an aprotic solvent or with at least one C.sub.3-C.sub.6 alcohol or with a solvent mixture of at least one C.sub.3-C.sub.6 alcohol, preferably tBuOH and an aprotic solvent to provide preferably tBuOH/MeCN 1:4; or eluting of [.sup.18F]fluoride with the solution of the compound of formula (IV) provided in step (A1), preferably in MeOH concentrating of the resulting solution and redissolving of the residue in an aprotic solvent, preferably in DMSO; (A7) allowing the compound of formula (IV) to react with [.sup.18F]fluoride in order to obtain the compound of the formula (III); ##STR00127## wherein A, B, C, D, OL and R.sup.1 have the same meanings as defined above; and (A8) purifying of the compound of formula (III).

17. A method for preparing a compound of formula (I) which comprises using a compound of formula (II) as defined in claim 1 in the method; ##STR00128## wherein A, B, C, and D represent independently of each other C—H, C—F, C—Cl, or N; and not more than two of A, B, C, and D represent N; E represents a covalent bond or ##STR00129## ##STR00130##  wherein R.sup.1 represents C.sub.1-C.sub.3 alkyl, C.sub.1-C.sub.3 alkoxy, C.sub.1-C.sub.3 haloalkyl, C.sub.1-C.sub.3 thioalkyl, perfluoroalkyl, C.sub.1-C.sub.3 haloalkoxy, C.sub.1-C.sub.4 alkylcarbonyl, C.sub.1-C.sub.4 alkoxycarbonyl, C.sub.1-C.sub.4 alkylcarboxy, aryloxy, alkylaryl, aryl, arylcarboxy, halogen, preferably Cl or Br, trifluoromethyl, cyano or nitro; n is an integer selected from 0 to 10; n.sub.1 is an integer selected from 0 to 10; n.sub.2 is an integer selected from 0 to 10; m is an integer selected from 1 to 18; p is an integer selected from 0 to 10; q is an integer selected from 1 to 18; X, Y, W, and Z represent independently of each other —CH.sub.2—, —CH—, —NH—, or —N; represents a single or double bond; and diastereomers, enantiomers, hydrates, and salts thereof.

18. A method for preparing a compound of formula (I) as defined in claim 3, ##STR00131## comprising the steps: (A) providing a solution of a compound of formula (II) in a polar protic solvent, preferably in EtOH, or in a solvent mixture containing a polar protic solvent containing at least one base, preferably in Et.sub.4NHCO.sub.3; ##STR00132## (B) providing a solution of a compound of formula (III) ##STR00133## wherein A, B, C, D and R.sup.1 have the meanings as defined, and OL represents a leaving group, optionally wherein the residue L of the leaving group OL in formula (III) represents preferably: ##STR00134## and wherein R.sup.5 is selected from methyl, ethyl, or n-propyl, further optionally wherein the compound (III) is selected from the group comprising: ##STR00135## in a polar protic solvent, preferably in EtOH, or in a solvent mixture containing a polar protic solvent; (C) mixing the solution of the compound of formula (II) and the solution of the compound of formula (III) and allowing the compound of formula (II) to react with the compound of formula (III) in order to obtain the compound of formula (I), (D) purifying the compound of formula (I), preferably by using isotonic sodium chloride solution.

19. Method according to claim 18, wherein step (C) is performed at a reaction temperature T2 which is in the range of 30° C. to 60° C., preferably 20° to 60° C., wherein the reaction time t2 of step (C) is optionally 1-30 min, and wherein the pH value of the reaction solution in step (C) is optionally in the range of 7.0-11.0.

20. Method according to claim 18, wherein the compound of formula (III) does not require purification via HPLC, and/or wherein the method does not comprise the application of a base and any other additives, preferably not activators selected from Kryptofix® and 18-crown-6; and/or wherein the method comprises the application of only onium salt precursor (IV) and [.sup.18F]fluoride; and/or wherein the method does not comprise any azeotropic drying steps; and/or wherein the method does not require any evaporation steps.

21. Method according to claim 18, wherein the compound of formula (I) does not require purification via HPLC, and wherein the method comprises the application of environmentally benign solvents such as ethanol, n-propanol, and butandiol-1,4, triglycol glycerol, triglycerol; and/or wherein the method does not comprise any evaporation steps, and/or wherein the method does not require any deprotection steps, wherein said deprotection steps may be steps of p-methoxybenzyl (PMB) or tBu deprotection using anisol/TFA mixture; and/or wherein the method does not require a neutralization step; and/or wherein the method does not require a formulation step, and/or wherein the method does not require toxic solvents.

22. Method according to claim 18 further comprising the following step (E) after the step (D): (E) sterilizing the solution of the compound of formula (I) via sterile filtration.

23. Method according to claim 18 further comprising the following steps (A1)-(A8) as defined in claim 18 after step (A) and before step (B).

24. Method according to claim 18 further comprising the following step (F) after the step (D) or (E): (F) preparing a pharmaceutical composition containing the solution of the compound of formula (I).

25. Method according to claim 18, wherein the base in step (A) is an organic nitrogen-containing base or a bicarbonate, wherein the bicarbonate is preferably a quaternary ammonium bicarbonate or hydrogenphosphate.

26. Method according to claim 25, wherein the organic nitrogen-containing base or the bicarbonate is selected from the group comprising: LiHCO.sub.3, NaHCO.sub.3, KHCO.sub.3, CsHCO.sub.3, Me.sub.4NHCO.sub.3, Me.sub.4NHPO.sub.4, Et.sub.4NHCO.sub.3, Et.sub.4NHPO.sub.4, n-Pr.sub.4NHCO.sub.3, n-Pr.sub.4NHPO.sub.4, i-Pr.sub.4NHCO.sub.3, n-Bu.sub.4NHCO.sub.3, n-Bu.sub.4NHPO.sub.4, BzlMe.sub.3NHCO.sub.3, BzlMe.sub.3NHPO.sub.4, BzlEt.sub.3NHCO.sub.3, BzlEt.sub.3NHPO.sub.4, BzlBu.sub.3NHCO.sub.3, BzlBu.sub.3NHPO.sub.4, Et.sub.3N, pyridine, lutidine, collidine, diisopropylethylamine, n-Pr.sub.3N, i-Pr.sub.3N, n-Bu.sub.3N, i-Bu.sub.3N, Oct.sub.3N, N-methyl-morpholine, N-ethylmorpholine, N-methylpiperidine, N-ethylpiperidine, N,N-dicyclohexylmethylamine N,N-dimethylcyclohexylamine, N-methyl-dibutylamine, N-ethyldicyclohexylamine, N,N-dimethylbutylamine, and N,N-dimethylhexylamine.

27. Method according to claim 18, wherein the polar protic solvent in step A6 is an anhydrous polar protic solvent, preferably anhydrous EtOH, preferably in methods without evaporation step, or anhydrous MeOH in methods comprising an evaporation step.

28. Method according to claim 18, wherein the [.sup.18F]fluoride is trapped on an anion exchange resin and then eluted directly.

29. Method according to claim 18, wherein the C.sub.3-C.sub.6 alcohol is tBuOH, tertAmOH, or pinacol.

30. Method according to claim 18, wherein the compound of the formula (I) is selected from the group consisting of compounds 1-3, 1-10, 1-14, 1-17, 1-29, 1-31, 1-32, 1-33, and 1-34: ##STR00136## ##STR00137##

31. A kit for carrying out the method of claim 18 comprising one or more containers containing the compounds of formula (II) and (III), optionally a packaged pharmaceutical compositions comprising a pharmaceutically acceptable carrier, further optionally comprising instructions for preparing compounds according to the invention from supplied precursors and/or instructions for using the composition to image cells or tissues.

32. (canceled)

Description

DESCRIPTION OF FIGURES

[0228] FIG. 1: Automatic synthesis of [.sup.18F]DCFPyL with HPLC purification in a TRACERLab FX.sub.fn automated radiochemistry synthesis module (GE Medical Systems).

[0229] FIG. 2: [.sup.68Ga]HBED-CC- (50) versus [.sup.18F]DCFPyL (1-10)-PET in PSMA.sup.+ PCa bearing mice. Shown are measurements in the same animal, on two consecutive days. Cursor position is indicated by crosslines. Abbreviations: K: kidney; T: tumor. Scale bar: 10 mm.

[0230] FIG. 3: Automatic synthesis of [.sup.18F]DCFPyL without HPLC purification in a TRACERLab FX.sub.fn automated radiochemistry synthesis module (GE Medical Systems). Reference signs A to I in FIG. 3 have the following meaning:

TABLE-US-00002 A 3 mL EtOH (absolute) B 200 μL [.sup.18F]F—Py-TFP-precursor solution C 2 mL tBuOH/MeCN (4:1) D 10 mL H.sub.2Or E 15 mL H.sub.2O F 500 μL [.sup.18F]DCFPyL-precursor solution G 3 mL H.sub.2O H 10 mL H.sub.2O I 60 mL 1.7% H.sub.3PO.sub.4 J 9 mL Isotonic NaCl K 2 mL Isotonic NaCl with 50 Vol % EtOH L 10 mL H.sub.2O M 20 mL 0.1% TFA

[0231] FIG. 4: Automated cassette module synthesis of [.sup.18F]DCFPyL 1-10 starting from [.sup.18F]fluoride without HPLC purification

EXAMPLES

Abbreviations:

[0232] βAla (beta-alanine), Boc (tert-butyloxycarbonyl), DCC (N,N′-dicyclohexylcarbodiimide), DMF (dimethylformamide), DMM (dimethoxymethane), DMSO (dimethyl sulfoxide), EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide), EDTA (ethylenediaminetetraacetic acid), Glu (glutanic acid), Gly (glycine), Lys or syL (lysine) mCPBA (meta-chloroperoxy benzoic acid), MeCN (acetonitrile), ONSu (N-oxy-succinimide), OTf (trifluoromethanesulfonate), Tos (tosyl), PMB (p-methoxybenzyl), Py (pyridinyl), tBu (tert-butyl), TFA (trifluoroacetic acid), TFE (tetrafluoroethyl alcohol), TFP (2,3,5,6-tetrafluorophenyl), THF (tetrahydrofuran), TIS (triisopropylsilane), TMS (trimethylsilyl).

Example 01: Preparation of 2,3,5,6-Tetrafluorophenyl-6-[.SUP.18.F]fluoronicotinate ([.SUP.18.F]F-Py-Tfp, 3c)

[0233] ##STR00073##

Procedure A:

[0234] Aqueous [.sup.18F]fluoride (0.05-50 GBq) was trapped on a anion-exchange resin (QMA or Chromafix® 30-PS—HCO.sub.3 cartridge). It should be noted, that in the case of QMA cartridges, the aqueous [.sup.18F]fluoride was loaded onto the cartridge from the male side, whereas EtOH flushing and .sup.18F.sup.− elution were done from the female side of the cartridge. The cartridge was washed with EtOH (1 mL) and [.sup.18F]fluoride was eluted from the resin into the reaction vial with N,N,N-trimethyl-5-[(2,3,5,6-tetrafluorophenoxy)-carbonyl]pyridine-2-aminium trifluoromethanesulfonate 4c (10 mg, 20 μmoL) in EtOH (200 μL) followed by MeCN/tBuOH 1:4 (2 mL). The mixture was stirred for 15 min at 40° C. After cooling to ambient temperature, the reaction mixture was diluted with water (20 mL) and loaded onto a polymer RP cartridge (the cartridge was preconditioned with 2 mL EtOH followed by 30 mL H.sub.2O). The cartridge was washed H.sub.2O (5 mL) and [.sup.18F]F-Py-Tfp 3c (up to 15 GBq, 70-75% EOB; not decay corrected) was eluted with EtOH (300 μL). The radiochemical and chemical purities after SPE purification were >98% determined by analytical HPLC (Eluent: Water with 50% MeCN. Flow rate: 1.5 mL/min. Column: Chromolith® SpeedROD RP-18e column (Merck, Darmstadt Germany), 50×4.6 mm. Retention time: [.sup.18F]F-Py-Tfp 3c˜2 min).

Procedure B:

[0235] Aqueous [.sup.18F]fluoride (0.05-50 GBq) was trapped on a anion-exchange resin (QMA or Chromafix® 30-PS—HCO.sub.3 cartridge). It should be noted, that in the case of QMA cartridges, the aqueous [.sup.18F]fluoride was loaded onto the cartridge from the male side, whereas EtOH flushing and .sup.18F.sup.− elution were done from the female side of the cartridge. [.sup.18F]fluoride was eluted from the resin into the reaction vial with methanolic tetraethylammonium bicarbonate solution (5 mg, 500 μL). The solvent was removed under reduced pressure at 70 C within 2 min. Afterwards precursor dissolved in MeCN/tBuOH 1:4 (2 mL) was added and the mixture was stirred for 15 min at 40° C. After cooling to ambient temperature, the reaction mixture was diluted with water (20 mL) and loaded onto a polymer RP cartridge (the cartridge was preconditioned with 2 mL EtOH followed by 30 mL H.sub.2O). The cartridge was washed H.sub.2O (5 mL) and [.sup.18F]F-Py-Tfp 3c (up to 15 GBq, 70-75% EOB; not decay corrected) was eluted with EtOH (300 μL). The radiochemical and chemical purities after SPE purification were >98% determined by analytical HPLC (Eluent: Water with 50% MeCN. Flow rate: 1.5 mL/min. Column: Chromolith® SpeedROD RP-18e column (Merck, Darmstadt Germany), 50×4.6 mm. Retention time: [.sup.18F]F-Py-Tfp 3c˜2 min).

Example 02: Preparation of [.SUP.18.F]DCFPyL 1-10

[0236] ##STR00074##

[0237] To a freshly prepared ethanolic solution of HO-Lys-C(O)-Glu-OH 2b (2.5 mg, 100 μL) and tetraethylammonium bicarbonate (0.5 M) in EtOH (60 μL) an ethanolic solution of [.sup.18F]F-Py-Tfp 3c (0.05-10 GBq in 150 μL) was added. The reaction mixture was stirred for 3 min at 40° C. Afterwards the mixture was quenched with water (2 mL) and purified by preparative HPLC. Eluent: saline (0.9% NaCl) with 10% EtOH. Flow rate: 8 mL/min. Column: Synergi 4 μm Hydro-RP 80 Å 100×21.2 mm. Retention time: ˜7 min. The purified product was sterile filtered before use. [.sup.18F]DCFPyL 1-10 was obtained in 75-90% RCY (decay-corrected). The radiochemical and chemical purities after HPLC purification were >98%, determined by analytical HPLC: Eluent: phosphoric acid buffer solution (pH=2) with 10% EtOH for 5 min, then 50% for 2 min. Flow rate: 1.5 mL/min. Column: Chromolith® SpeedROD RP-18e column (Merck, Darmstadt Germany), 50×4.6 mm. Retention times: [.sup.18F]DCFPyL˜3 min; [.sup.18F]F-Py-Tfp˜5.7 min).

Example 03: Automated Synthesis of [.SUP.18.F]DCFPyL 1-10 Starting from [.SUP.18.F]Fluoride Using Final HPLC Purification (FIG. 1)

[0238] Aqueous [.sup.18F]fluoride (0.05-50 GBq) was vacuum-transferred from the target to a trapping vial. Aqueous [.sup.18F]fluoride was then transferred from the trapping vial through an anion-exchange resin cartridge (QMA) from the male side of the cartridge, and [.sup.18O]H.sub.2O was collected in a separate vial. The cartridge was subsequently washed with EtOH (1 mL) from vial A from the female side of the cartridge. Washings were discarded. Thereafter, [.sup.18F]fluoride was eluted from the resin with N,N,N-trimethyl-5-[(2,3,5,6-tetrafluorophenoxy)-carbonyl]pyridine-2-aminium trifluoromethanesulfonate 4c (10 mg, 20 μmoL) in EtOH (200 μL) from vial B into reactor R1. After this, MeCN/tBuOH 1:4 (2 mL) from vessel C was passed through the cartridge into reactor R1. Reactor R1 was filled with helium, sealed and the reaction mixture was heated at 45° C. for 20 min. After cooling to room temperature the crude [.sup.18F]F-Py-Tfp 3c was transferred into the collecting vial C1, containing 20 mL H.sub.2O. The solution was passed through a polymer RP cartridge (Strata X). The cartridge was washed with H.sub.2O (5 mL) from reservoir D and dried by applying a helium stream for 5 min. [.sup.18F]F-Py-Tfp 3c was eluted with EtOH (400 μL) from vial E into reactor R2 containing a mixture of a freshly prepared ethanolic solution of HO-syL-C(O)-Glu-OH 2b (2.5 mg, 100 μL) and 0.5 M tetraethylammonium bicarbonate in EtOH (60 μL). After addition of [.sup.18F]F-Py-Tfp, the reaction mixture was heated at 40° C. for 3 min. After cooling to room temperature the reaction mixture was diluted with H.sub.2O (2 mL) from vial F and [.sup.18F]DCFPyL was loaded onto the HPLC for purification. The crude tracer was purified by preparative HPLC to give [.sup.18F]DCFPyL 1-10 in 40-65% RCY (from .sup.18F.sup.−; decay-corrected) in ≧95% radiochemical purity. Eluent: saline (0.9% NaCl) with 10% EtOH. Flow rate: 8 mL/min. Column: Synergi 4 am Hydro-RP 80 Å 100×21.2 mm. Retention time: ˜7 min. The purified product was sterile filtered before use as (determined by analytical HPLC (Quality control): Eluent: phosphoric acid buffer solution (pH=2) with 10% EtOH for 5 min, then phosphoric acid buffer solution (pH=2) with 50% EtOH for 2 min. Flow rate: 1.5 mL/min. Column: Chromolith® SpeedROD RP-18e column (Merck, Darmstadt Germany), 50×4.6 mm. Retention times: [.sup.18F]DCFPyL˜3 min; [.sup.18F]F-Py-Tfp˜5.7 min).

##STR00075##

Example 04: Preparation of 2,3,5,6-Tetrafluorophenyl 4-Iodobenzoate 20

[0239] ##STR00076##

[0240] Et.sub.3N (1.504 mL, 0.76 g, 7.51 mmol) was added dropwise to a vigorously stirred solution of 4-iodobenzoyl chloride 19 (2 g, 7.51 mmol) and 2,3,5,6-tetrafluorophenol (1.25 g, 7.51 mmol) in Et.sub.2O (60 mL) and the stirring was continued for a further 10 min. The reaction mixture was filtered, the filter cake was washed with Et.sub.2O (30 mL) and the filtrate was concentrated under reduced pressure. The residue was dissolved Et.sub.2O (10 mL) and filtered. The filtrate was concentrated under reduced pressure. The residue was recrystallized from Et.sub.2O/hexane to give the title compound (1.38 g, 48%) as a colorless solid.

[0241] R.sub.f=0.46, EtOAc:hexane=1:10.

[0242] .sup.1H-NMR (CDCl.sub.3, 300 MHz): δ=7.07 (tt, J=9.9, 7.1 Hz, 1H), 7.82-7.98 (m, 4H);

[0243] .sup.19F-NMR (CDCl.sub.3, 282.4 MHz): δ=−152.70, −138.80;

[0244] .sup.13C-NMR (CDCl.sub.3, 75.5 MHz): δ=103.0, 103.4 (t, J=23.0 Hz), 126.6, 131.9, 138.3, 138.9-142.7 (m), 144.4 (dt, J=3.8, 12.1 Hz), 147.7 (dt, J=4.5, 12.1 Hz), 162.2. MS (ESI): positive mode m/z=397.3 ([M+H].sup.+). MS (EI, 70 eV): m/z (%): 395.9 [M.sup.+] (3), 230.9 [C.sub.7H.sub.4OI.sup.+] (100), 202.9 [C.sub.6H.sub.3I.sup.+] (100), 104.0 [C.sub.7H.sub.4O] (10).

Example 05: Preparation of (4-Methoxyphenyl) [4-(2,3,5,6-tetrafluorophenoxycarbonyl)phenyl]iodonium tosylate 21

[0245] Tos.H.sub.2O (0.72 g, 3.79 mmol) was added to a solution of 2,3,5,6-tetraphenyl 4-iodobenzoate 20 (1 g, 2.52 mmol), mCPBA [1.44 g, 85% purity, 7.09 mmol; commercially available 77% mCPBA (Aldrich) was dried at 2 mbar and 40° C. for 3 h before use] and anisole (0.51 mL, 0.51 g, 4.72 mmol) in 50% CF.sub.3CH.sub.2OH (TFE) in CH.sub.2Cl.sub.2 (20 mL) and the mixture was stirred for 3 days. The reaction mixture was added to vigorously stirred Et.sub.2O (450 mL) and stirring was continued for a further 45 min. The precipitate was filtered off and washed with Et.sub.2O (100 mL), redissolved in CH.sub.2Cl.sub.2 (20 mL) and filtered through Celite®. The filtrate was concentrated under reduced pressure. The residue was recrystallized from CH.sub.2Cl.sub.2/Et.sub.2O to give the title compound (1.53 g, 90%) as a colorless solid.

[0246] .sup.1H-NMR (CDCl.sub.3, 300 MHz): δ=2.28 (s, 3H), 3.77 (s, 3H), 6.80 (d, J=9.0 Hz, 2H), 6.97 (d, J=6.0 Hz, 2H), 7.01-7.14 (m, 1H), 7.36 (d, J=9.0 Hz, 2H), 7.98-8.03 (m, 4H), 8.18 (d, J=9.0 Hz, 2H);

[0247] .sup.19F-NMR (CDCl.sub.3, 282.4 MHz): δ=−152.70, −138.55;

[0248] .sup.13C-NMR (CDCl.sub.3, 75.5 MHz): δ=21.2, 55.5, 103.7 (t, J=23.0 Hz), 104.7, 117.4, 123.0, 125.9, 128.5, 129.3, 132.7, 135.3, 137.9, 138.8-423142.3 (m), 139.6, 142.2, 144.4 (dt, J=3.8, 15.9 Hz), 147.7 (dt, J=4.5, 16.6 Hz), 161.3, 162.4.

[0249] MS (ESI): positive mode m/z=503.0 ([M]+); MS (ESI): negative mode m/z=171.0 ([C.sub.7H.sub.7SO.sub.3].sup.−); ESI HRMS: calcd for C.sub.20H.sub.12F.sub.4O.sub.3I.sup.+: 502.9762; found: 502.9769.

Example 06: Preparation of (4-Methoxyphenyl) [4-(2,3,5,6-tetrafluorophenoxycarbonyl)phenyl]iodonium iodide 22

[0250] (4-Methoxyphenyl)[4-(2,3,5,6-tetrafluorophenoxycarbonyl)phenyl]iodonium tosylate 21 (1.19 g, 1.76 mmol) was dissolved in CH.sub.2Cl.sub.2 (20 mL). After addition of saturated NaI (10 mL), the mixture was vigorously stirred for 15 min and centrifuged (4000 rpm, 15° C., 10 min). The aqueous solution and precipitate were separated off, saturated NaI (10 mL) was added and the mixture was vigorously stirred for 15 min and centrifuged (×3). The organic fraction was filtered, dried and concentrated under reduced pressure. The residue was recrystallized from CH.sub.2Cl.sub.2/Et.sub.2O, the precipitate was filtered off, washed with acetone (10 mL) and Et.sub.2O (80 mL) to give the title compound (0.29 g, 26%) as an off-white solid. The substance could be stored at 4° C. under argon at least for 4 months. However, it was unstable in solution especially at elevated temperatures (dissolved in DMF or DMSO it was unstable already at ambient temperature).

[0251] .sup.1H-NMR (CDCl.sub.3, 300 MHz): δ=3.79 (s, 3H), 6.65-6.73 (m, 2H), 6.95-7.10 (m, 1H), 7.56 (d, J=8.9 Hz, 2H), 7.81-8.05 (m, 3H), 8.21-8.35 (m, 1H);

[0252] .sup.19F-NMR (CDCl.sub.3, 282.4 MHz): δ=−152.63, −138.72;

[0253] .sup.13C-NMR (CDCl.sub.3, 75.5 MHz): δ=55.5, 82.3, 103.0, 103.5 (t, J=22.6 Hz), 116.4, 126.6, 128.8, 131.9, 138.3, 138.6-142.5 (m), 144.2-144.7 (m), 144.5-144.9 (m), 159.5, 162.2.

[0254] MS (ESI): positive mode m/z=502.9 ([M]+); MS (ESI): negative mode m/z=126.9 ([I].sup.−);

[0255] ESI HRMS: calcd for C.sub.20H.sub.12F.sub.4O.sub.3+: 502.9762; found: 502.9741.

Example 07: Preparation of (4-Methoxyphenyl) [4-(2,3,5,6-tetrafluorophenoxycarbonyl)phenyl]iodonium perchlorate 4a

[0256] To a solution of (4-methoxyphenyl)[4-(2,3,5,6-tetrafluorophenoxycarbonyl)phenyl]-iodonium iodide 22 (0.2 g, 0.32 mmol) in acetone (12 mL) and AgClO.sub.4 (66 mg, 0.32 mmol) was added. The reaction mixture was shaken for 1 min, precipitated AgI was separated by centrifugation. The supernatant was concentrated under reduced pressure and the residue was recrystallized from CH.sub.2Cl.sub.2/Et.sub.2O to give the title compound (168 mg, 88%) as a colorless solid.

[0257] .sup.1H-NMR (CDCl.sub.3, 300 MHz): δ=3.80 (s, 3H), 6.88-6.98 (m, 2H), 7.06 (tt, J=9.9, 7.1 Hz, 1H), 8.04-8.13 (m, 2H), 8.14-8.18 (m, 2H), 8.21-8.26 (m, 2H);

[0258] .sup.19F-NMR (CDCl.sub.3, 282.4 MHz): δ=−152.52, −138.48;

[0259] .sup.13C-NMR (CDCl.sub.3, 75.5 MHz): δ=55.5, 101.1, 103.8 (t, J=21.1 Hz), 118.4, 120.1, 130.6, 133.5, 135.1, 138.3, 138.7-139.3 (m), 142.1-144.4 (m), 147.5-147.7 (m), 161.0, 163.4.

[0260] MS (ESI): positive mode m/z=503.0 ([M].sup.+); ESI HRMS: calcd for C.sub.20H.sub.12F.sub.4O.sub.3I.sup.+: 502.9762; found: 502.9769. MS (ESI): positive mode m/z=503.0 ([M].sup.+); MS (ESI): negative mode m/z=171.0 ([C.sub.7H.sub.7SO.sub.3].sup.−); ESI HRMS: calcd for C.sub.20H.sub.12F.sub.4O.sub.3I.sup.+: 502.9762; found: 502.9749.

Example 08: Preparation of 2,3,5,6-tetrafluorophenyl 4-fluorobenzoate 24

[0261] ##STR00077##

[0262] Et.sub.3N (0.54 mL, 0.39 g, 3.87 mmol) was added dropwise to a vigorously stirred solution of 4-fluorobenzoyl chloride 25 (0.46 mL, 0.61 g, 3.87 mmol) and 2,3,5,6-tetrafluorophenol (0.64 g, 3.87 mmol) in Et.sub.2O (30 mL) and the stirring was continued for a further 10 min. The reaction mixture was filtered, washed with H.sub.2O (15 mL) and brine (2×10 mL), dried and concentrated under reduced pressure. The residue was recrystallized from hexane to give 24 (0.41 g) as a colorless solid. The mother liquor was concentrated under reduced pressure and the residue was recrystallized from hexane to give a second crop of 24 (0.45 g, total 77%).

[0263] R.sub.f=0.62, EtOAc:hexane=1:10.

[0264] .sup.1H-NMR (CDCl.sub.3, 300 MHz): δ=7.07 (tt, J=9.9, 7.1 Hz, 1H), 7.21-7.30 (m, 2H), 8.21-8.37 (m, 2H);

[0265] .sup.19F-NMR(CDCl.sub.3, 282.4 MHz): δ=−152.75, −138.93, −102.24;

[0266] .sup.13C-NMR (CDCl.sub.3, 75.5 MHz): δ=103.4 (t, J=21.9 Hz), 116.2 (d, J=21.9 Hz), 123.5 (d, J=1.5 Hz), 133.5 (d, J=2.3 Hz), 139.0-142.7 (m), 144.5-145.1 (m), 147.3-148.2 (m), 163.3 (d, J=259.7 Hz), 168.5. MS (ESI): positive mode m/z=288.3 ([M]+). MS (EI, 70 eV): m/z (%): 165.0 [C.sub.6HF.sub.4O.sup.+] (10), 123.0 [C.sub.6H.sub.4FO.sup.+] (100), 95.0 [C.sub.6H.sub.4F.sup.+] (10).

Example 09: Preparation of 2,3,5,6-tetrafluorophenyl 4-[.SUP.18.F]fluorobenzoate 3a

[0267] Aqueous [.sup.18F]fluoride (0.05-50 GBq) was trapped on a anion-exchange resin (QMA or Chromafix® 30-PS—HCO.sub.3 cartridge). It should be noted, that in the case of QMA cartridges, the aqueous [.sup.18F]fluoride was loaded onto the cartridge from the male side, whereas MeOH flushing and .sup.18F-elution was done from the female side of the cartridge. If the QMA cartridge has been loaded, flushed and eluted from the female side only, sometimes a significant amount of [.sup.18F]fluoride remained on the resin (this is probably because QMA-light (46 mg) cartridges have a single frit on the male side but four on the female side). The cartridge was washed with MeOH (1 mL) and [.sup.18F]fluoride was eluted into a reaction vial with a solution of (4-methoxyphenyl) [4-(2,3,5,6-tetrafluorophenoxycarbonyl)phenyl]iodonium perchlorate (5 mg) 4a in MeOH (0.5 mL). Methanol was evaporated under reduced pressure at 70° C. within 2-3 min. After cooling to room temperature DMSO (500 VL) was added. The reaction mixture was stirred at 130° C. for 10 min. Subsequently the mixture was cooled down to room temperature, water (4 mL) was added and the reaction mixture was shaken vigorously for 30 s. Analysis of the mixture by radio-HPLC showed formation of the desired .sup.18F-labelled active ester in 24% RCY. HPLC conditions: column: Chromolith® SpeedROD RP-18e (Merck, Darmstadt Germany), 50×4.6 mm; eluent: 50% MeCN; flow rate: 3 mL/min.

Example 10: Preparation of 2,3,5,6-tetrafluorophenyl 6-[.SUP.18.F]fluoropyridazine-3-carboxylate (3e)

[0268] ##STR00078##

[0269] 3e can be prepared from radiolabelled precursor 4e using one of two alternative radiolabelling procedures. According to the first one .sup.18F.sup.− is fixed on an anion exchange resin. The resin is washed with EtOH and drained. .sup.18F is eluted with an ethanolic solution of 4e. The resin is additionally washed with tBuOH/MeCN 1:4 and the collected eluates are heated for a short time. Finally 3e is isolated via SPE. Alternatively 3e is eluted with methanolic tetraethylammonium bicarbonate, the solvent is evaporated and the residue is taken up in a solution of 4e in tBuOH/MeCN 1:4 and heated for a short time. Finally the desired active ester is isolated via SPE. Radiolabelling precursor 4e can be prepared from commercially available precursor 14 as follows: Esterification with 1,2,5,6-tetrafluorophenol/DCC, treatment of the intermediate active ester 15 with anhydrous trimethylamine in THF followed by anion metathesis using TMSOTf. The reference compound 18 can be prepared from intermediate 15 by treatment with AgF under anhydrous conditions.

Example 11: Preparation 2,3,5,6-tetrafluorophenyl 5-[.SUP.18.F]fluoropyrazine-2-carboxylate (3f)

[0270] ##STR00079##

[0271] Compound 3f can be prepared exactly as 3e as described in the Example 10.

Example 12: Preparation of 2,3,5,6-tetrafluorophenyl 4-[.SUP.18.F]fluoro-2,3,5,6-tetrafluorobenzoate (3d)

[0272] ##STR00080## ##STR00081##

[0273] Compound 3d can be prepared exactly as 3e as described in the Example 10.

Example 13: Preparation of (2S)-2-({[(1S)-1-carboxy-5-{[6-[.SUP.18.F]fluoropyridazin-3-yl]formamido}pentyl]carbamoyl}amino)butanedioic acid (1-17)

[0274] ##STR00082##

[0275] Compound 1-17 can be prepared exactly as [.sup.18F]DCFPyL (1-10) as described in the Example 2.

Example 14: Preparation of (2S)-2-({[(1S)-1-carboxy-5-{[5-[.SUP.18.F]fluoropyrazin-2-yl]formamido}pentyl]carbamoyl}amino)butanedioic acid (1-29)

[0276] ##STR00083##

[0277] Compound 1-29 can be prepared exactly as [.sup.18F]DCFPyL ([.sup.18F] 1-10) as described in the Example 2.

Example 15: Preparation of (2S)-2-({[(1S)-1-carboxy-5-(3-{[6-[.SUP.18.F]fluoropyridin-3-yl]formamido}propanamido)pentyl]carbamoyl}amino)butanedioic acid (1-31)

[0278] ##STR00084##

[0279] Compound 1-33 can be prepared analogously to [.sup.18F]DCFPyL ([.sup.18F]1-10) using 2d instead of 2b. 2d can in turn be prepared using conventional methods of peptide synthesis, for example, via acylation of known 37 with Boc-βAla-ONSu followed by cleavage of protecting groups.

Example 16: Preparation of (2S)-2-({[(1 S)-1-carboxy-5-(2-{[6-[.SUP.18.F]fluoropyridazin-3-yl]formamido}acetamido)pentyl]carbamoyl}amino)butanedioic acid (1-32)

[0280] ##STR00085##

[0281] Compound 1-32 can be prepared analogously to [.sup.18F]DCFPyL (1-10) using 2p instead of 2b. 2p can in turn be prepared using conventional methods of peptide synthesis, for example, via acylation of known 37 with Boc-Gly-Gly-ONSu followed by cleavage of protecting groups.

Example 17: Preparation of (2S)-2-({[(1S)-1-carboxy-5-[(4S)-4-carboxy-4-{[4-[.SUP.18.F]fluoro-2,3,5,6-tetrafluorophenyl]formamido}butanamido]pentyl]carbamoyl}amino)butanedioic acid (1-33)

[0282] ##STR00086##

[0283] Compound 1-33 can be prepared analogously to [.sup.18F]DCFPyL (1-10) using 2k instead of 2b. 1-33 can in turn be prepared using conventional methods of peptide synthesis, for example, via acylation of known 37 with Boc-Glu(ONSu)-OtBu followed by cleavage of protecting groups.

Example 18: Preparation of (2S)-2-({[(1S)-1-carboxy-5-[(4S)-4-carboxy-4-[(4S)-4-carboxy-4-{[6-[.SUP.18.F]fluoropyridin-3-yl]formamido}butanamido]butanamido]-pentyl]carbamoyl}amino)butanedioic acid (1-34)

[0284] ##STR00087##

[0285] Compound 1-34 can be prepared analogously to [.sup.18F]DCFPyL ([.sup.18F]1-10) using 2n instead of 2b. 2n can in turn be prepared using conventional methods of peptide synthesis, for example, via acylation of known 37 with Z-Glu(ONSu)-OtBu followed by cleavage of Z (Z=benzyloxycarbonyl, Boc=tert-butyloxycarbonyl) group, followed by acylation of intermediate 49 with Boc-Glu(ONSu)-OtBu and final deprotection with TFA.

Example 19: Comparison of [.SUP.18.F]DCFPyL ([.SUP.18.F]1-10) with [.SUP.68.Ga]HBED-CC (50) in PSMA.SUP.+.-PCa Xenograft Mice

[0286] ##STR00088##

Methods:

[0287] Five 8-week-old male C.B-Igh-1b/IcrTac-Prkdcscid mice (Taconic) were injected subcutaneously in the neck region with 4×10.sup.6 LNCaP-C4-2 prostate tumor cells. Three weeks after tumor implantation, two PET measurements with [.sup.18F]DCFPyL ([.sup.18F]1-10) and [.sup.68Ga]HBED-CC (50), respectively, were performed using an Inveon μPET/CT scanner (Siemens) with a resolution of 1.4 mm FWHM at center of field of view. The first PET measurement was immediately followed by a CT scan during which the animal was left in the same position. Both tracers were injected i.v. through the lateral tail vein ([.sup.18F]1-10: 21-32 MBq; [.sup.68Ga]HBED-CC: 19-33 MBq, on two consecutive days). Emission data collection started 60 min after injection and lasted 45 min. Image reconstruction was performed using Fourier rebinning and an ordered subset expectation maximization (3D-OSEM) procedure, yielding images with voxel sizes of 0.78×0.78×0.80 mm. Image analysis was performed with VINCI 4.0 (MPI for Metabolism Research, Cologne, Germany). Tracer uptake in the tumor as well as liver, kidney, and background was determined using volumes of interest (VOIs) covering the respective structure. Significant differences were assessed using two-way repeated measures ANOVA with factors “structure” and “tracer”, followed by Holm-Sidak post hoc comparison. Tumor sizes were measured by drawing accurate tumor VOIs in the CT images, and extracting VOI volume. Tracer uptake was correlated tumor size using the Pearson correlation test.

Results

[0288] As shown in FIG. 2, tumor tracer uptake was similar for the two tracers (FIG. 2): 1.4±1.7% ID/g for [.sup.18F]1-10, and 1.8±2.0% ID/g for [.sup.68Ga]HBED-CC (50) (not significant). There was a significant positive correlation between tumor size and tracer uptake for both tracers: R=0.97, p=0.0059 for [.sup.18F]1-10, and R=0.98, p=0.0019 for [.sup.68Ga]HBED-CC (50). Signal-to-noise ratio (tumor versus background) was nearly identical as well with 5.9±4.2 for [.sup.18F]1-10, and 6.7±6.9 for [.sup.68Ga]HBED-CC (50). While liver uptake was similar as well (1.1±0.5% ID/g for [.sup.18F]1-10, and 0.7±0.2% ID/g for [.sup.68Ga]HBED-CC (50); not significant), [.sup.18F]1-10 uptake in the kidney (3.0±1.9% ID/g) was significantly lower than [.sup.68Ga]HBED-CC (50) uptake (13.9±6.4% ID/g; F(3,12)=25.6, p<0.0001 for factor interaction, post-hoc p<0.05).

Example 20: Automated Synthesis of [.SUP.18.F]DCFPvL 1-10 Starting from [.SUP.18.F]Fluoride without HPLC Purification (FIG. 3)

[0289] Aqueous [.sup.18F]fluoride (0.05-50 GBq) was transferred from the target to a trapping vial. Aqueous [.sup.18F]fluoride was then vacuum-transferred from the trapping vial through an anion-exchange resin cartridge (Sep-Pak QMA carbonate light 46 mg, preconditioned with 1 mL water) from the male side of the cartridge, and [.sup.18O]H.sub.2O was collected in a separate vial. The cartridge was subsequently washed with EtOH (3 mL) from vial A from the female side of the cartridge. Washings were discarded. Thereafter, [.sup.18F]fluoride was slowly eluted from the resin with N,N,N-trimethyl-5-[(2,3,5,6-tetrafluorophenoxy)-carbonyl]pyridine-2-aminium trifluoromethanesulfonate 4c (10 mg, 20 μmoL) in EtOH (200 μL) from the vial B into reactor R1 with a low flow of helium. After this, MeCN/tBuOH 1:4 (2 mL) from vessel C was passed through the cartridge into reactor R1. Reactor R1 was filled with helium, sealed and the reaction mixture was heated at 45° C. for 15 min. After cooling to room temperature the crude [.sup.18F]F-Py-Tfp 3c was diluted with water (15 mL) from vessel E and passed through a polymer RP cartridge (Strata X, preconditioned with 1 mL EtOH and washed with 5 mL water). The cartridge was washed with H.sub.2O (10 mL) from reservoir D and dried by applying a helium stream for 5 min. [.sup.18F]F-Py-Tfp 3c was eluted with a mixture of ethanol (250 μL), freshly prepared ethanolic solution of HO-syL-C(O)-Glu-OH 2b (2.5 mg, 100 μL) and 0.5 M tetraethylammonium bicarbonate in EtOH (60 μL) from vial F into reactor R2. The reaction mixture was heated at 40° C. for 3 min. After cooling to room temperature the reaction mixture was diluted with water from vial G and transferred to vessel M containing 0.1% TFA (20 mL). The acidic solution was loaded onto a tC18 cartridge (Sep-Pak tC18 Plus Long Cartridge, 900 mg, preconditioned with 10 mL EtOH and washed with 30 mL water). The cartridge was subsequently washed with water (10 mL) from vial H and [.sup.18F]DCFPyL was eluted with 10% EtOH-solution of 1.7% phosphoric acid (60 mL) onto a HLB catridge (Oasis HLB Plus Short Cartridge 225 mg, preconditioned with 10 mL EtOH and washed with 30 mL water) from Vessel I. The HLB cartridge was washed with 10 mL water by vessel L and [.sup.18F]DCFPyL was eluted with 50 Vol % ethanol in isotonic saline (2 mL; v/v). The solution was diluted with isotonic saline (9 mL) and sterile filtered. Quality control: eluent: phosphoric acid (1.7%) with 10% EtOH for 5 min, then with 50% EtOH for 2 min. Flow rate: 3 mL/min. Column: Chromolith® SpeedROD RP-18e column (Merck, Darmstadt Germany), 50×4.6 mm. Retention times: [.sup.18F]DCFPyL˜3 min; [.sup.18F]F-Py-Tfp˜5.7 min.

Example 21: Automated Cassette Module Synthesis of [.SUP.18.F]DCFPyL 1-10 Starting from [.SUP.18.F]Fluoride without HPLC Purification (FIG. 4)

[0290] Aqueous [.sup.18F]fluoride (0.05-50 GBq) was transferred from the target to the receiver vial at position E. Aqueous [.sup.18F]fluoride was then vacuum transferred from the receiver vial E through an anion-exchange resin cartridge (Sep-Pak QMA carbonate light 46 mg, preconditioned with 1 mL water) via CPBaA. [.sup.18O]H.sub.2O was collected in the collection vial. The cartridge was subsequently washed with EtOH (1 mL) from reservoir D by action of syringe 1 (S1) via DS1 and then S1BCWaste two times. Thereafter, [.sup.18F]fluoride was slowly eluted from the resin with N,N,N-trimethyl-5-[(2,3,5,6-tetrafluorophenoxy)-carbonyl]pyridine-2-aminium trifluoromethanesulfonate 4c (10 mg, 20 μmoL) in EtOH (200 μL) from the vial at position J into the reactor via JS1 and then S1BCG. The reaction solvent MeCN/tBuOH 1:4 (2 mL) from vessel at position K was passed through the cartridge into the reactor via KS1 and then S1BCG, too. The reactor was sealed and the reaction mixture was heated at 50° C. for 15 min. The crude [.sup.18F]F-Py-Tfp 3c was purified by SPE. This was accomplished by a stepwise dilution procedure of the crude reaction mixture. At first the hot reaction mixture was quenched with water (2 ml) from the reservoir at position M by action of syringe 2 (S2) via MS2 and then S2G. Then syringe 2 was partially filled with water (5.5 mL) via MS2, and an aliquot (1 mL) crude [.sup.18F]F-Py-Tfp was sucked into the syringe 2 via GS2. The diluted solution was passed through a small C18 cartridge (Sep-Pak C18 Plus Light Cartridge, 130 mg) at position H via S2HRWaste. The whole procedure was repeated until full recovery of the reaction mixture was achieved. The cartridge was washed with water (5 mL) via MS2 and S2HRWaste, and dried with a nitrogen stream for 20 s via AHRWaste. The reactor, manifold, the tubing HR and syringe 1 was thoroughly cleaned by a procedure involving flushing with ethanol and dried with a stream of nitrogen. The [.sup.18F]F-Py-Tfp 3c was eluted from the small C.sub.18 cartridge with a solution of HO-syL-C(O)-Glu-OH 2b (2.5 mg) and 0.5 M tetraethylammonium bicarbonate in EtOH (500 VL) from vial at position L into reactor via LRHG by applying vacuum at VReactor. The reaction mixture was heated at 40° C. for 3 min and, thereafter, quenched with 0.5% trifluoroacetic acid (4 mL) from vessel at position N via NS2 and S2G. The acidic solution of [.sup.18F]DCFPyL was further diluted with H.sub.2O and loaded onto a tC18 cartridge (Sep-Pak tC18 Plus Long Cartridge, 900 mg, preconditioned with 5 mL EtOH and washed with 15 mL water). To achieve this, syringe 2 was partially filled with water (4 mL) via MS2, then an aliquot of the crude reaction mixture (1 mL) was sucked into the syringe 2 via GS2. This solution was passed through the tC18 cartridge (Sep-Pak C18 Plus Light Cartridge, 130 mg) via S2HRWaste. The whole dilution procedure was performed at least four times to archive full recovery of the reaction mixture in the reactor. The cartridge was subsequently washed with water (5 mL) from the reservoir via MS2 and S2HRWaste, and dried by applying a high flow nitrogen stream for 5 s via AHRWaste. The [.sup.18F]DCFPyL was stepwise eluted from the tC.sub.18 phase with 10 Vol % EtOH-solution of 1.7% phosphoric acid (total volume of 60 mL) onto a HLB cartridge (Oasis HLB Plus Short Cartridge 225 mg, preconditioned with 5 mL EtOH and washed with 15 mL water) from vessel at position O by action of syringe 2 via OS2 and then S2PQSTWaste to archive further purification. After this, the HLB cartridge was washed with 10 mL water via MS2 and then S2STWaste. The purified [.sup.18F]DCFPyL was eluted with ethanol (1 mL) from reservoir D via DS1 into syringe 3 (S3) via S1STS3. The ethanolic [.sup.18F]DCFPyL solution in syringe 3 was further diluted with isotonic saline (total volume of 10 mL) from vessel I via ISTS3 and dispensed upon operators request into the tracer vial at position U (S3U) with simultaneous sterile filtration to give the PET-tracer as a ready for injection solution in 9% EtOH in isotonic saline. Quality control: eluent: 1.7% phoshoric acid/EtOH=9/1 for 5 min, then 1.7% phoshoric acid/EtOH=1/1 for 2 min. Flow rate: 3 mL/min. Column: Chromolith® SpeedROD RP-18e column (Merck, Darmstadt Germany), 50×4.6 mm. Retention times: [.sup.18F]DCFPyL˜3 min; [.sup.18F]F-Py-Tfp˜5.7 min.

Additional Embodiments of the Invention

[0291] 1. A method for preparing a compound of formula (I)

##STR00089## [0292] wherein [0293] A, B, C, and D represent independently of each other C—H, C—F or N; and not more than two of A, B, C, and D represent N; [0294] E represents a covalent bond or

##STR00090## [0295] R.sup.1 represents C.sub.1-C.sub.3 alkyl, C.sub.1-C.sub.3 alkoxy, C.sub.1-C.sub.3 haloalkyl, C.sub.1-C.sub.3 haloalkoxy, C.sub.2-C.sub.4 alkylcarbonyl, C.sub.2-C.sub.4 alkyloxycarbonyl, C.sub.2-C.sub.4 alkylcarboxy, aryloxy, arylcarboxy, cyano, or nitro; [0296] n is an integer selected from 0 to 10; [0297] m is an integer selected from 1 to 18; [0298] p is an integer selected from 0 to 10; [0299] X, Y, W, and Z represent independently of each other —CH.sub.2—, —CH—, —NH— or —N—; [0300] represents a single or double bond; [0301] and diastereomers, enantiomers, hydrates, and salts thereof; [0302] comprising the steps: [0303] (A) providing a solution of a compound of formulae (II) in a polar protic solvent or in a solvent mixture containing a polar protic solvent containing at least one base

##STR00091## [0304] wherein E and p have the meanings as defined above, [0305] (B) providing a solution of a compound of formula (III)

##STR00092## [0306] wherein A, B, C, D and R.sup.1 have the meanings as defined above, and OL represents a leaving group [0307] in a polar protic solvent or in a solvent mixture containing a polar protic solvent; [0308] (C) mixing the solution of the compound of formula (II) and the solution of the compound of formula (III) and allowing the compound of formula (II) to react with the compound of formula (III) in order to obtain the compound of formula (I), [0309] (D) purifying the compound of formula (I) preferably by using isotonic sodium chloride solution. [0310] 2. Method according to embodiment 1, wherein step (C) is performed at a reaction temperature T2 which is in the range of 30° C. to 60° C. and during a reaction time t2 which is 1-30 min and at a pH value of the reaction solution which is in the range of 7.0-11.0. [0311] 3. Method according to embodiment 1 or 2, wherein L in the leaving group OL represents:

##STR00093## [0312] and wherein R.sup.5 is selected from methyl, ethyl, or n-propyl; [0313] 4. Method according to embodiments 1, 2 or 3 further comprising the following step (E) after the step (D): [0314] (E) sterilizing the solution of the compound of formula (I) via steril filtration. [0315] 5. Method according to embodiments 1, 2, 3 or 4 further comprising the following steps (A1)-(A8) after step (A) and before step (B): [0316] (A1) providing a solution of a compound of the formula (IV) in at least one polar protic solvent or in a solvent mixture containing a polar protic solvent, [0317] wherein optionally the solution further contains a salt;

##STR00094## [0318] wherein [0319] A, B, C, D, OL and R.sup.1 have the same meanings as defined in embodiment 1; [0320] X represents NR.sup.2.sub.3, IR.sup.3, SR.sup.3.sub.2; [0321] Y represents Br, I, BF.sub.4, O.sub.2CCF.sub.3, OSO.sub.2CF.sub.3, ClO.sub.4, NO.sub.2, OSO.sub.2C.sub.6H.sub.4CH.sub.3, OSO.sub.2CH.sub.3 [0322] R.sup.2 represents C.sub.1-C.sub.4 alkyl; and [0323] R.sup.3 represents aryl; [0324] (A2) providing an aqueous solution of [.sup.18F]fluoride; [0325] (A3) loading the aqueous solution of [.sup.18F]fluoride onto an anion exchange resin; [0326] (A4) washing the anion exchange resin with a polar protic solvent or with a polar aprotic solvent; [0327] (A5) flushing of the solvent with air or inert gas flow; [0328] (A6) eluting of [.sup.18F]fluoride with the solution of the compound of formula (IV) provided in step (A1) and diluting of the resulting solution with an aprotic solvent or with at least one C.sub.3-C.sub.6 alcohol or with a solvent mixture of at least one C.sub.3-C.sub.6 alcohol and an aprotic solvent; or [0329] eluting of [.sup.18F]fluoride with the solution of the compound of formula (IV) provided in step (A1), concentrating of the resulting solution and redissolving of the residue in an aprotic solvent; [0330] (A7) allowing the compound of formula (IV) to react with [.sup.18F]fluoride in order to obtain the compound of the formula (III);

##STR00095## [0331] wherein A, B, C, D, OL and R.sup.1 have the same meanings as defined in embodiment 1; and [0332] (A8) purifying of the compound of formula (III). [0333] 6. Method according to any one of the embodiments 1-5 further comprising the following step (F) after the step (D) or (E): [0334] (F) preparing a pharmaceutical composition containing the solution of the compound of formula (I). [0335] 7. Method according to any one of the embodiments 1-6, wherein the base in step (A) is an organic nitrogen-containing base or a bicarbonate. [0336] 8. Method according to embodiment 7, wherein the organic nitrogen-containing base or the bicarbonate is selected from the group consisting of: LiHCO.sub.3, NaHCO.sub.3, KHCO.sub.3, CsHCO.sub.3, Me.sub.4NHCO.sub.3, Et.sub.4NHCO.sub.3, n-Pr.sub.4NHCO.sub.3, i-Pr.sub.4NHCO.sub.3, n-Bu.sub.4NHCO.sub.3, i-Bu.sub.4NHCO.sub.3, Et.sub.3N, pyridine, lutidine, collidine, diisopropylethylamine, n-Pr.sub.3N, i-Pr.sub.3N, n-Bu.sub.3N, i-Bu.sub.3N, Oct.sub.3N, N-methyl-morpholine, N-ethylmorpholine, N-methylpiperidine, N-ethylpiperidine, N,N-dicyclohexylmethylamine, N,N-dimethylcyclohexylamine, N-methyl-dibutylamine, N-ethyldicyclohexylamine, N,N-dimethylbutylamine, and N,N-dimethylhexylamine [0337] 9. Method according to any one of the embodiments 1-8, wherein the polar protic solvent is an anhydrous polar protic solvent, especially anhydrous MeOH or anhydrous EtOH or a mixture thereof. [0338] 10. Method according to any one of the embodiments 1-9, wherein the compound (III) is

##STR00096## [0339] 11. Method according to any one of the embodiments 5-10, wherein the [.sup.18F]fluoride is trapped on an anion exchange resin and then eluted directly. [0340] 12. Method according to any one of the embodiments 5-11, wherein the C.sub.3-C.sub.6 alcohol is tBuOH. [0341] 13. Method according to any one of the embodiments 1-12, wherein the compound of the formula (I) is selected from the group consisting of compounds 1-3, 1-10, 1-14, 1-17, 1-29, 1-31, 1-32, 1-33, and 1-34:

##STR00097## ##STR00098## [0342] 14. Pharmaceutical composition containing at least one compound of formula (I) as defined in embodiment 1 together with at least one pharmaceutically acceptable solvent, ingredient and/or diluent. [0343] 15. Pharmaceutical composition according to embodiment 14 for use in imaging prostate cancer cells or prostate cancerous tissue. [0344] 16. A method for preparing a compound of formula (I)

##STR00099## [0345] wherein [0346] A, B, C, and D represent independently of each other C—H, C—F or N; [0347] and not more than two of A, B, C, and D represent N; [0348] E represents a covalent bond or

##STR00100## [0349] R.sup.1 represents C.sub.1-C.sub.3 alkyl, C.sub.1-C.sub.3 alkoxy, C.sub.1-C.sub.3 haloalkyl, C.sub.1-C.sub.4 alkylcarboxy, aryloxy, arylcarboxy, cyano, or nitro; [0350] n is an integer selected from 0 to 10; [0351] m is an integer selected from 1 to 18; [0352] p is an integer selected from 0 to 10; [0353] X, Y, W, and Z represent independently of each other —CH.sub.2—, C—H, —NH— or N; [0354] represents a single or double bond; [0355] and diastereomers, enantiomers, hydrates, and salts thereof; [0356] comprising the steps: [0357] (A) providing a solution of a compound of formulae (II) in a polar protic solvent or in a solvent mixture containing a polar protic solvent containing at least one base

##STR00101## [0358] wherein E and p have the meanings as defined above, [0359] (B) providing a solution of a compound of formula (III)

##STR00102## [0360] wherein [0361] A, B, C, D and R.sup.1 have the meanings as defined above, and [0362] OL represents a leaving group [0363] in a polar protic solvent or in a solvent mixture containing a polar protic solvent; [0364] (C) mixing the solution of the compound of formula (II) and the solution of the compound of formula (III) and allowing the compound of formula (II) to react with the compound of formula (III) in order to obtain the compound of formula (I), [0365] (D) purifying the compound of formula (I). [0366] 17. Method according to embodiment 16, wherein step (C) is performed at a reaction temperature T2 which is in the range of 30° C. to 60° C. and during a reaction time t2 which is 1-30 min and at a pH value of the reaction solution which is in the range of 7.0-11.0. [0367] 18. Method according to embodiment 16 or 17, wherein L in the leaving group OL represents:

##STR00103## [0368] and wherein R.sup.5 is selected from methyl, ethyl, or n-propyl; [0369] 19. Method according to any one of embodiments 16 to 18 further comprising the following step (E) after the step (D): [0370] (E) sterilizing the solution of the compound of formula (I) via sterile filtration. [0371] 20. Method according to any one of embodiments 16 to 19 further comprising the following steps (A1)-(A8) after step (A) and before step (B): [0372] (A1) providing a solution of a compound of the formula (IV) in at least one polar protic solvent or in a solvent mixture containing a polar protic solvent, [0373] wherein optionally the solution further contains a salt;

##STR00104## [0374] wherein [0375] A, B, C, D, OL and R.sup.1 have the same meanings as defined in claim 1; [0376] X represents NR.sup.2.sub.3, IR.sup.3, SR.sup.3.sub.2; [0377] Y represents Br, I, BF.sub.4, O.sub.2CCF.sub.3, OSO.sub.2CF.sub.3, ClO.sub.4, NO.sub.2, OSO.sub.2C.sub.6H.sub.4CH.sub.3, OSO.sub.2CH.sub.3 [0378] R.sup.2 represents C.sub.1-C.sub.4 alkyl; and [0379] R.sup.3 represents aryl; [0380] (A2) providing an aqueous solution of [.sup.18F]fluoride; [0381] (A3) loading the aqueous solution of [.sup.18F]fluoride onto an anion exchange resin; [0382] (A4) washing the anion exchange resin with a polar protic solvent or with a polar aprotic solvent; [0383] (A5) flushing of the solvent with air or inert gas flow; [0384] (A6) eluting of [.sup.18F]fluoride with the solution of the compound of formula (IV) provided in step (A1) and diluting of the resulting solution with an aprotic solvent or with at least one C.sub.3-C.sub.6 alcohol or with a solvent mixture of at least one C.sub.3-C.sub.6 alcohol and an aprotic solvent; [0385] or [0386] eluting of [.sup.18F]fluoride with the solution of the compound of formula (IV) provided in step (A1), concentrating of the resulting solution and redissolving of the residue in an aprotic solvent; [0387] (A7) allowing the compound of formula (IV) to react with [.sup.18F]fluoride in order to obtain the compound of the formula (III);

##STR00105## [0388] wherein A, B, C, D, OL and R.sup.1 have the same meanings as defined in claim 1; and [0389] (A8) purifying of the compound of formula (III). [0390] 21. Method according to any one of the embodiments 16-20 further comprising the following step (F) after the step (D) or (E): [0391] (F) preparing a pharmaceutical composition containing the solution of the compound of formula (I). [0392] 22. Method according to any one of the embodiments 16 to 21, wherein the base in step (A) is selected from the group consisting of: [0393] LiHCO.sub.3, NaHCO.sub.3, KHCO.sub.3, CsHCO.sub.3, Me.sub.4NHCO.sub.3, Et.sub.4NHCO.sub.3, n-Pr.sub.4NHCO.sub.3, n-Bu.sub.4NHCO.sub.3, Et.sub.3N, pyridine, lutidine, collidine, diisopropylethylamine, n-Bu.sub.3N, Oct.sub.3N, N-methylmorpholine, N-ethylmorpholine, N-methylpiperidine, N-ethylpiperidine, N,N-dicyclohexylmethylamine, N,N-dimethylcyclohexylamine, N-methyldibutylamine, N-ethyldicyclohexylamine, N,N-dimethylbutylamine, and N,N-dimethylhexylamine. [0394] 23. Method according to any one of the embodiments 16 to 22, wherein the polar protic solvent is MeOH or EtOH. [0395] 24. Method according to any one of the embodiments 16 to 23, wherein the compound (III) is

##STR00106## [0396] 25. Method according to any one of the embodiments 20-24, wherein the [.sup.18F]fluoride is trapped on an anion exchange resin and then eluted directly. [0397] 26. Method according to any one of the embodiments 20-24, wherein the C.sub.3-C.sub.6 alcohol is tBuOH. [0398] 27. Method according to any one of the embodiments 16-26, wherein the compound of the formula (I) is selected from the group consisting of compounds 1-3, 1-10, 1-14, 1-17, 1-29, 1-31, 1-32, 1-33, and 1-34:

##STR00107## ##STR00108## [0399] 28. Pharmaceutical composition containing at least one compound of formula (I) as defined in embodiment 16 together with at least one pharmaceutically acceptable solvent, ingredient and/or diluent. [0400] 29. Pharmaceutical composition according to embodiment 28 for use in imaging prostate cancer cells or prostate cancerous tissue.