Reinforced macrocyclic ligands, complexes thereof, and uses of same

Abstract

Ligands that are based on the pyclen macrocycle that are reinforced, which are useful for complexing elements such as radioelements and/or elements with magnetic properties.

Claims

1. A compound of formula (I) ##STR00039## wherein: X.sub.1, X.sub.2, X.sub.3, Y.sub.1, Y.sub.2, Y.sub.3, Y.sub.4, Y.sub.5 and Y.sub.6 are independently selected from the group consisting of: H, (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, (C.sub.6-C.sub.10)aryl, halogen, azide (—N.sub.3), —C(O)ORa, —ORa, —N(Ra)(Rb), —C(O)—N(Ra)(Rb), —SH, —SRa, —SO.sub.2OH, —SO.sub.2—N(Ra)(Rb), —SCN, and a functional chemical group which allows grafting to a vector or to a biomolecule wherein said functional chemical group is selected from the group consisting of succinimidyl, N-hydroxysuccinimidyl, sulfosuccinimidyl, maleimidyl, biotinyl, squarate, and ##STR00040## wherein R1 is an alkylene, thiol, azide, hydrazine and isothiocyanate, wherein Ra and Rb are independently either H or (C.sub.1-C.sub.20)alkyl group; and wherein: one or more of said alkyl, alkenyl, and alkynyl groups optionally comprises one or more heteroatoms, one or more (C.sub.6-C.sub.10)arylenes, and/or one or more biphenylene(s) in its/their chain(s); and one or more of said alkyl, alkenyl, alkynyl, and (C.sub.6-C.sub.20)aryl groups optionally is substituted with one or more substituent(s) selected from the group consisting of: halogen, —C(O)ORc, —ORc, —N(Rc)(Rd), —C(O)-N(Rc)(Rd), —SH, —SRc, —SO.sub.2OH, —SO.sub.2—N(Rc)(Rd) —SCN, (C.sub.6-C.sub.10)aryl, and a functional chemical group which allows grafting to a vector or a biomolecule wherein said functional chemical group is selected from the group consisting of succinimidyl, N-hydroxysuccinimidyl, sulfosuccinimidyl, maleimidyl, biotinyl, squarate, and ##STR00041## wherein R1 is an alkylene, thiol, azide, hydrazine and isothiocyanate; wherein Rc and Rd are independently either H or a (C.sub.1-C.sub.20)alkyl group, wherein said (C.sub.1-C.sub.20)alkyl group is optionally substituted with one or more substituent(s) selected from the group consisting of: halogen, —C(O)ORe, —ORe, —N(Re)(Rf), —C(O)—N(Re)(Rf), —SH, —SRe, —SO.sub.2OH, —SO.sub.2—N(Re)(Rf) —SCN, (C.sub.6-C.sub.10)aryl, and a functional chemical group which allows grafting to a vector or a biomolecule wherein said functional chemical group is selected from the group consisting of succinimidyl, N-hydroxysuccinimidyl, sulfosuccinimidyl, maleimidyl, biotinyl, squarate, and ##STR00042## wherein R1 is an alkylene, thiol, azide, hydrazine and isothiocyanate; and wherein Re and Rf are independently either H or a (C.sub.1-C.sub.20)alkyl group; Z.sub.1 and Z.sub.2 are independently selected from the group consisting of: H, (C.sub.1-C.sub.4)alkyl, halogen, —ORg, —N(Rg)(Rh), —SH, and —SRg; wherein Rg and Rh are independently selected from the group consisting of: H, a (C.sub.1-C.sub.4)alkyl, 2-THP (tetrahydropyranyl), tosyl, nosyl or TMS (trimethylsilyl) group, —O—C(O)Rt, —C(O)Rt, —OC(O)ORt, —NH-C(O)—ORt, and —NH—C(O)Rt; and wherein Rt is selected from the group consisting of: (C.sub.1-C.sub.4)alkyl, benzyl, allyl, and trifluoromethyl; wherein one or more of said alkyl groups is optionally substituted with one or more substituent(s) selected from the group consisting of: halogen, —C(O)ORp, —ORp, —N(Rp)(Rq), —C(O)—N(Rp)(Rq), —SH, —SRp, —SO.sub.2OH, —SO.sub.2—N(Rp)(Rq), and —SCN; wherein Rp and Rq are independently either H or a (C.sub.1-C.sub.4)alkyl group; R is selected from the group consisting chosen from the group consisting of: H, (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, (C.sub.1-C.sub.20)alkylene-W, (C.sub.2-C.sub.20)alkenylene-W, and (C.sub.2-C.sub.20)alkynylene-W; wherein: one or more of said alkyl, alkenyl, alkynyl, alkylene, alkenylene, and alkynylene groups optionally comprise(s) one or more heteroatoms, one or more (C.sub.6-C.sub.10)arylenes, and/or one or more biphenylene(s) in its/their chain(s); W is selected from the group consisting of: (C.sub.6-C.sub.10)aryl, heteroaryl consisting 5 to 10 atoms, biphenyl, —C(O)ORi, —C(O)—N(Ri)(Rj), —P(O)(ORi)(ORj), —(Rj)P(O)(ORi), —O—P(O)(ORi)(ORj), —SH, —SO.sub.2OH, —SO.sub.2—N(RO(Rj) and —SCN; wherein Ri and Rj are independently either H or a (C.sub.1-C.sub.20)alkyl group; and one or more of said alkyl, alkenyl, alkynyl, alkylene, alkenylene, alkynylene, aryl and heteroaryl groups is optionally be substituted with one or more substituent(s) selected from the group consisting of: (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, halogen, —C(O)ORk, —ORk, —N(Rk)(RI), —C(O)—N(Rk)(RI), —SH, —SRk, —SO.sub.2OH, —SO.sub.2—N(Rk)(RI), —SCN, (C.sub.6-C.sub.10)aryl and biphenyl; wherein Rk and Rl are independently either H or a (C.sub.1-C.sub.20)alkyl group, wherein said alkyl is optionally substituted with one or more substituents selected from the group consisting of: halogen, —C(O)ORm, —ORm, —N(Rm)(Rn), —C(O)—N(Rm)(Rn), —SH, —SRm, —SO.sub.2OH, —SO.sub.2—N(Rm)(Rn), —SCN, (C.sub.6-C.sub.10)aryl, and a functional chemical group which allows grafting to a vector or a biomolecule wherein said functional chemical group is selected from the group consisting of succinimidyl, N-hydroxysuccinimidyl, sulfosuccinimidyl, maleimidyl, biotinyl, squarate, and ##STR00043## wherein R1 is an alkylene, thiol, azide, hydrazine and isothiocyanate; wherein Rm and Rn are independently either H a (C.sub.1-C.sub.20)alkyl group; or a pharmaceutically acceptable salt of formula (I), an optical isomer of formula (I), a geometric isomer of formula (I), a tautomer of formula (I), or a solvate of formula (I).

2. The compound of claim 1, wherein: R is selected from the group consisting of: H, (C.sub.1-C.sub.20)alkyl, (C.sub.1-C.sub.20)alkylene-W; wherein: W is selected from the group consisting of: (C.sub.6-C.sub.10)aryl, heteroaryl consisting of 5 to 10 atoms, —C(O)ORi, —C(O) —N(Ri)(Rj), —P(O)(ORi)(ORj), —(Rj)P(O)(ORi), —O-P(O)(ORi)(ORj), —SH, —SO.sub.2OH, —SO.sub.2—N(RO(Rj) and —SCN; wherein Ri and Rj are independently either H or a (C.sub.1-C.sub.20)alkyl group; and p one or more of said alkyl, alkylene, aryl and heteroaryl groups is optionally substituted with one or more substituent(s) chosen from the group consisting of: (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, halogen, —C(O)ORk, ORk, —N(Rk)(RI), —C(O)—N(Rk)(RI), —SH, —SRk, —SO.sub.2OH, —SO.sub.2—N(Rk)(RI), —SCN and (C.sub.6-C.sub.10)aryl; wherein Rk and RI are independently either H or a (C.sub.1-C.sub.20)alkyl group.

3. The compound of claim 1, wherein formula (I) corresponds to formula (II) set forth below ##STR00044##

4. The compound of claim 3, wherein X.sub.2 is H.

5. The compound of claim 1, wherein formula I corresponds to a structure selected from the group consisting of the following: ##STR00045## wherein Rk is H or a (C.sub.1-C.sub.20)alkyl group.

6. The compound of claim 1, wherein formula I corresponds to a structure selected from the group consisting of the following: ##STR00046## wherein Rk is H or a (C.sub.1-C.sub.4)alkyl group.

7. The compound of claim 1, wherein formula I corresponds to a structure selected from the group consisting of the following: ##STR00047## wherein Rk is t-butyl; and ##STR00048## wherein Rk is a t-butyl.

8. A complex comprising a central atom M and the compound of claim 1.

9. The complex of claim 8, wherein M is a metal.

10. A method for treating a patient suffering from a cancer, the method comprising administering to said patent a therapeutic amount of the complex of claim 8.

11. A contrast product comprising the complex of claim 8.

12. A pharmaceutical composition comprising the compound of claim 1 and, optionally, one or more pharmaceutically acceptable excipient(s).

13. A pharmaceutical composition comprising the complex of claim 8 and, optionally, one or more pharmaceutically acceptable excipient(s).

14. A process for preparing the compound of claim 1, the process comprising reducing a compound of formula (XIII) below: ##STR00049## wherein X.sub.1, X.sub.2, X.sub.3, Y.sub.1, Y.sub.2, Y.sub.3, Y.sub.4, Y.sub.5, Y.sub.6 and R are as defined for formula (I), in the presence of a mixture of a reducing agent A-BH.sub.4 and of an organic acid, wherein A is selected from the group consisting of Li, Na, K, Zn and (Me.sub.3)N, to obtain a compound of formula (I′) below: ##STR00050## wherein X.sub.1, X.sub.2, X.sub.3, Y.sub.1, Y.sub.2, Y.sub.3, Y.sub.4, Y.sub.5, Y.sub.6 and R are as defined for formula (I).

15. The process of claim 14, wherein A is Na and the organic acid is trifluoroacetic acid.

16. The process of claim 14 further comprising, before said reducing step, condensing a compound of formula (X) below: ##STR00051## wherein X.sub.1, X.sub.2, X.sub.3, Y.sub.1, Y.sub.2, Y.sub.3, Y.sub.4, Y.sub.5 and Y.sub.6 are as defined for formula (I), with a compound of formula (XI) below: ##STR00052## wherein is E a (C.sub.1-C.sub.4)alkyl, to obtain a compound of formula (XII) below: ##STR00053## wherein X.sub.1, X.sub.2, X.sub.3, Y.sub.1, Y.sub.2, Y.sub.3, Y.sub.4, Y.sub.5 and Y.sub.6 are as defined for formula (I).

17. The process of claim 16, wherein E is methyl or ethyl.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1: .sup.1H and .sup.13C NMR spectra of the compound 2a.

(2) FIG. 2: .sup.1H and .sup.13C NMR spectra of the [Zn(2a)](ClO.sub.4) complex.

(3) FIG. 3: Mass spectrometry of the compound 3a.

(4) FIG. 4: Mass spectrometry of the compound 4.

(5) FIG. 5: .sup.13C NMR spectrum of the compound 4 (CDCl.sub.3, 75.45 MHz, 298K).

(6) FIG. 6: Spectrum obtained by HPLC-MS during the analysis of the precipitate containing the compound 2c and the corresponding lactam.

(7) FIG. 7: Structure of the compound 11 obtained by X-ray diffraction.

(8) FIG. 8: Structure of the [Mn(2a)](ClO.sub.4) complex obtained by X-ray diffraction.

(9) The examples below are given by way of illustration and are not limiting with respect to the present invention.

EXAMPLES

(10) The acronyms used in the text below will have the following meanings: ACN: acetonitrile DCM: dichloromethane DIPEA: diisopropylethylamine EtOH: ethanol MeOH: methanol NaOH: sodium hydroxide AT: ambient temperature TFA: trifluoroacetic add THF: tetrahydrofuran

Example 1: Preparation of the Reinforced Ligands of Formula (I) According to the Invention

(11) 1—Condensing Step A According to the Invention:

(12) ##STR00035##

(13) A solution of diethyl oxalate (2.02 g, 13.8 mmol) in EtOH (100 ml) was added to a solution of pyclen 1″ (2.37 g, 11.5 mmol) in EtOH (200 ml). The mixture was stirred at ambient temperature overnight and then concentrated. The residue obtained was purified by alumina column chromatography (CH.sub.2Cl.sub.2/MeOH 98/2). The final product 2″ was obtained in the form of a white solid (0.548 g, 19%) and corresponds to a compound of formula (XII) according to the invention.

(14) .sup.1H NMR (300 MHz, CDCl.sub.3): δ 7.52 (t, 1H, .sup.3J=7.7 Hz), 7.02 (d, 1H, .sup.3J=7.9 Hz), 6.93 (d, 1H, .sup.3J=7.5 Hz), 5.59 (d, 1H, .sup.2J=16.2 Hz), 4.62 (ddd, 1H, .sup.2J=13.9 Hz, .sup.3J=11.1 Hz, .sup.3J=2.5 Hz), 4.08 (d, 1H, .sup.2J=16.6 Hz), 3.95 (d, 1H, .sup.2J=17.3 Hz), 3.77 (ddd, 1H, .sup.2J=13.9 Hz, .sup.3J=10.6 Hz, .sup.3J=4.52 Hz), 3.70 (d, 1H, .sup.2J=17.3 Hz), 3.5 (ddd, 1H, .sup.2J=12.4 Hz, .sup.3J=10.6 Hz, .sup.3J=4.5 Hz), 3.24 (dt, 1H, .sup.2J=13.9 Hz, .sup.3J=4.4 Hz), 3.13 (dt, 1H, .sup.2J=12.4 Hz, .sup.3J=4.1 Hz), 3.01 (dt, 1H, .sup.2J=12.2 Hz, .sup.3J=3.2 Hz), 2.83 (dt, 1H, .sup.2J=13.9 Hz, .sup.3J=3.0 Hz), 2.74 (td, 1H, .sup.2J=11.7 Hz, .sup.3J=2.3 Hz).

(15) .sup.13C NMR (75.47 MHz, CDCl.sub.3): δ 162.96, 161.23, 159.10, 153.42, 136.83, 120.58, 119.44, 55.40, 52.53, 47.89, 47.66, 44.61, 44.20

Other Embodiment

(16) A solution of diethyl oxalate (4.21 g, 28.49 mmol) in MeOH (100 ml) was added to a solution of pyclen 1″ (5.88 g, 28.49 mmol) in MeOH (200 ml). The mixture was stirred at ambient temperature overnight and then concentrated. The residue obtained was taken up in dichloromethane, then the solution was filtered and concentrated in order to remove the unreacted pyclen 1″. The solid was solubilized in methanol (5 ml) then ethyl acetate was added (150 ml). The crystals formed were filtered off and dried under vacuum. The final product 2″ was obtained in the form of white crystals (6.28 g, 85%) and corresponds to a compound of formula (XII) according to the invention.

(17) 2—Following Steps According to the Invention:

(18) The synthesis of compounds of formula (I) is carried out according to the following scheme:

(19) ##STR00036## ##STR00037##
Compound 1a—Functionalizing Step B

(20) The methyl ester of 6-chloromethylpyridine-2-carboxylic acid (711 mg, 3.85 mmol) is added to a solution of pyclen oxalate (1.0 g, 3.85 mmol) in acetonitrile (300 ml) in the presence of K.sub.2CO.sub.3 (1.5 g, 12 mmol). The reaction mixture is brought to reflux for four days, and is then filtered. The filtrate is concentrated, then is purified by column chromatography using neutral alumina as support (eluent: CH.sub.2Cl.sub.2/MeOH 98/2). After evaporation, the product 1a obtained is a yellow oil (1.56 g, 99%).

(21) .sup.1H NMR (300 MHz, CDCl.sub.3): δ 7.90-7.80 (m, 2H), 7.72 (t, 1H, .sup.3J=7.91 Hz), 7.38 (t, 1H, .sup.3J=7.72 Hz), 6.97 (d, 1H, .sup.3J=7.91 Hz), 6.65 (d, 1H, .sup.3J=7.54 Hz), 5.59 (d, 1H, .sup.2J=16.20 Hz), 4.70 (m, 1H), 4.19 (d, 1H, .sup.2J=14.3 Hz), 4.12, 3.92 (m, 2H), 3.93 (s, 3H), 3.86 (d, 1H, .sup.2J=14.3 Hz), 3.77-3.54 (m, 3H), 3.20 (m, 1H), 2.99-2.78 (m, 3H), 2.72 (m, 1H).

(22) .sup.13C NMR (75.47 MHz, CDCl.sub.3): δ 165.71, 163.43, 160.97, 159.82, 158.63, 154.21, 146.15, 137.69, 136.67, 127.42, 123.44, 120.45, 119.28, 59.90, 59.47, 56.75, 53.02, 52.51, 46.19, 44.97, 44.68.

(23) ESI-MS (CH.sub.3CN/H.sub.2O, 50/50): m/z 410.15 [M+H].sup.+, 432.10 [M+Na].sup.+.

(24) Compound 1c—Functionalizing Step B

(25) A solution of tert-butyl bromoacetate (0.668 g, 3.42 mmol) in acetontrile (100 ml) is added to a solution composed of pyclen oxalate (0.890 g, 3.42 mmol) and of K.sub.2CO.sub.3 (1.42 g, 10.3 mmol) in acetonitrile (150 ml). The reaction medium is stirred at ambient temperature for 24 h. The solvent is evaporated off and then the residue obtained is taken up in dichloromethane. The product is then filtered and then concentrated. The product 1c obtained is a yellow oil that will be used in the following step without additional purification (1.25 g).

(26) .sup.1H NMR (300 MHz, CDCl.sub.3): δ 7.28 (t, 1H, .sup.3J=7.7 Hz), 6.8 (d, 1H, .sup.3J=7.5 Hz), 6.63 (d, 1H, J=7.5 Hz), 5.26 (d, 1H, .sup.2J=16.6 Hz), 4.08 (m, 1H), 3.89 (d, 1H, .sup.2J=16.6 Hz), 3.68 (m, 4H), 3.0 (m, 4H), 2.77 (m, 2H), 2.52 (m, 1H), 1.18 (m, 9H).

(27) .sup.13C NMR (75.47 MHz, CDCl.sub.3): δ 170.65, 162.42, 159.73, 158.43, 153.60, 136.48, 119.67, 119.11, 80.37, 61.08, 56.45, 52.59, 52.07, 46.64, 46.07, 44.76, 27.61.

(28) ESI-HR-MS (positive, H.sub.2O) m/z calculated for [C.sub.19H.sub.27N.sub.4O.sub.4].sup.+, 375.2027; obtained 375.2027 [M+H].sup.+, calculated for [C.sub.19H.sub.26N.sub.4O.sub.4Na].sup.+, 397.1846; obtained 397.1846 [M+Na].sup.+, calculated for [C.sub.15H.sub.19N.sub.4O.sub.4].sup.+, 319.1400; obtained 319.1400 [M-tBu+2H].sup.+.

(29) Compound 1c″—Functionalizing Step B

(30) A solution of methyl bromoacetate (587 mg; 3.38 mmol) in acetonitrile (13 ml) is added to a solution composed of pyclen oxalate (1.0017 g; 3.38 mmol) and of K.sub.2CO.sub.3 (796 mg; 5.76 mmol) in acetonitrile (13 ml). The reaction medium is stirred at ambient temperature for 4 h. After evaporation, the foam obtained is taken up in ethyl acetate (100 ml) and washed with the minimum amount of water (3 ml). The organic phase is dried over MgSO.sub.4, filtered and evaporated to give the product 1c′ in the form of a white foam (1.093 g; 97%)

(31) .sup.1H NMR (300 MHz, CDCl.sub.3): δ 7.48 (t, J=7.6 Hz, 1H), 7.00 (d, J=7.6 Hz, 1H), 6.83 (d, J=7.5 Hz, 1H), 5.55 (d, J=16.5 Hz, 1H), 4.46-4.27 (m, 1H), 4.14-3.80 (m, 4H), 3.62 (s, 3H), 3.45 (d, J=18.0 Hz, 1H), 3.34-3.20 (m, 2H), 3.15 (d, J=11.9 Hz, 1H), 2.96 (d, J=10.2 Hz, 2H), 2.77-2.56 (m, 1H).

(32) .sup.13C NMR (75.47 MHz, CDCl.sub.3): δ 172.33, 162.83, 160.22, 158.84, 154.07, 136.87, 120.11, 119.48, 61.46, 57.08, 52.34, 52.13, 51.19, 46.82, 46.38, 45.33

(33) Compound 2a—Obtaining a Nonreinforced Pyclen not Belonging to the Invention

(34) Hydrochloric acid (20 ml, 3 M) is added to the compound 1a (0.200 g, 0.49 mmol). The reaction medium is brought to reflux for 24 h and is then concentrated. The desired compound 2a is a colored oil (190 mg, 86% calculated for the hydrochloride salt).

(35) .sup.1H NMR (300 MHz, D.sub.2O): δ 8.19 (t, 1H), 8.01 (d, 1H), 7.88 (d, 1H), 7.61 (t, 1H), 7.23 (d, 1H), 6.95 (d, 1H), 4.54 (s, 2H), 4.52 (s, 2H), 4.18 (s, 2H), 3.57 (m, 2H), 3.42-3.30 (m, 6H).

(36) .sup.13C NMR (75.47 MHz, D.sub.2O): δ 166.48, 163.95, 157.07, 154.55, 153.60, 147.50, 146.03, 142.48, 132.14, 128.92, 125.91, 125.67, 61.36, 60.27, 54.61, 52.09, 46.73, 45.76.

(37) ESI-HR-MS (positive, H.sub.2O) m/z calculated for [C.sub.18H.sub.24N.sub.5O.sub.2].sup.+ 342.192451, obtained: 342.192738 [M+H].sup.+; calculated for [C.sub.18H.sub.23N.sub.5NaO.sub.2].sup.+ 364.174396, obtained: 384.174089 [M+Na].sup.+; calculated for [C.sub.18H.sub.23N.sub.5O].sup.2+: 162.594582, obtained: 162.594105 [M+2H—H.sub.2O].sup.2+; calculated for [C.sub.18H.sub.25N.sub.5O.sub.2].sup.2+ 171.599864, obtained: 171.599371 [M+2H].sup.2+

(38) Compound 2c—Obtaining a Nonreinforced Pyclen not Belonging to the Invention

(39) The compound 1c′ (338.9 mg, 1.01 mmol) is solubilized in ultrapure hydrochloric acid (10 ml, 3 M). The reaction mixture is heated at 70′C for 2.5 days and is then evaporated. The brown oil is taken up in the minimum amount of HCl and the product is precipitated with acetone (20 ml). The precipitate is analyzed on C-18 HPLC (H.sub.2O 0.1% TFA/ACN 0.1% TFA; 98/2>10/90) to give a separatable mixture of the expected product 2c and of the corresponding lactam.

(40) FIG. 6 provides the spectrum obtained by HPLC-MS.

(41) T.sub.R=8 min: m/z: calculated for [C.sub.13H.sub.19N.sub.4O].sup.+: 247.15, obtained: 247.20 [M+H].sup.+

(42) T.sub.R=12.5 min: m/z: calculated for [C.sub.13H.sub.21N.sub.4O.sub.2].sup.+: 265.16, obtained: 265.20 [M+H].sup.+

(43) Compound 10a—Reducing Step C

(44) Under an inert atmosphere, a solution of trifluoroacetic acid (1.984 g, 17.4 mmol) in anhydrous THF (5 ml) is slowly added to a suspension of NaBH.sub.4 (693 mg, 18.3 mmol) in anhydrous THF (5 ml) cooled to 0° C. The reaction mixture is stirred at the same temperature for 5 minutes. The compound 1a (452.8 mg, 1.11 mmol) solubilized in a THF/DCM 1:1 mixture (10 ml) is then slowly added to the reaction medium. The mixture is stirred at the same temperature for 10 min, then overnight at ambient temperature. Water and 10 M sodium hydroxide are added in order to neutralize the excess NaBH.sub.3OCOCF.sub.3. The borane is then extracted with DCM (3×20 ml), and the combined organic phases are dried over MgSO.sub.4, filtered on a frit and evaporated off. The compound 10a is thus obtained without additional purification (white foam; 227.5 mg; 54%)

(45) .sup.13C NMR (75.47 MHz, D.sub.2O): δ 165.34, 159.02, 158.67, 153.76, 147.27, 138.50, 137.81, 125.61, 124.54, 124.36, 123.73, 69.58, 67.54, 60.53, 60.19, 60.06, 55.30, 47.66

(46) ESI-MS (CH.sub.3CN/H.sub.2O, 50/50): m/z calculated for [C.sub.21H.sub.28N.sub.5O.sub.2].sup.+ 382.22, obtained 382.15 [M+H−2BH.sub.3].sup.+

(47) Compound 10c—Reducing Step C

(48) In a 50 ml round-bottomed flask, under argon, a solution of trifluoroacetic acid (1.559 g; 13.68 mmol) in anhydrous THF (6 ml) is added dropwise to a suspension of NaBH.sub.4 (545.3 mg; 14.4 mmol) in anhydrous THF (6 ml) cooled to 0° C. The reaction mixture is stirred at the same temperature for 5 min, then a solution of the compound 1c′ (321.2 mg; 0.96 mmol) in dichloromethane (4 ml) is added dropwise to the reducing agent at 0′C. The reaction mixture is stirred for 10 min at the same temperature, then at 30° C. overnight. After 18 hours, the precipitate is filtered off on a frit of porosity 4, then a solution of NaOH (10 M; 4 ml) is added to the filtrate, as are ultrapure H.sub.2O (15 ml) and DCM (20 ml). The desired product is then extracted with DCM (3×20 ml), and the combined organic phases are dried over MgSO.sub.4, filtered on a frit and evaporated off. The compound 10c is thus obtained without additional purification (white foam; 250.4 mg; 82%)

(49) .sup.13C NMR (75.47 MHz, CDCl.sub.3): δ 170.94, 158.77, 153.42, 138.41, 124.45, 124.21, 69.33, 67.44, 60.07, 59.04, 53.57, 51.16, 45.09.

(50) ESI-MS (CH.sub.3CN/H.sub.2O, 50/50): m/z calculated for [C.sub.16H.sub.25N.sub.4O.sub.2].sup.+ 305.19, obtained 305.15

(51) Compounds 3a and 13a—Hydrolysis Step

(52) Compound 10a (204.9 mg; 0.53 mmol) is solubilized in ultrapure HCl (3M; 2.6 ml). The reaction mixture is stirred at 40° C. for 4 days, then at reflux for 2 days. The water is evaporated off. An oil is obtained. This oil is then purified by C18-HPLC chromatography (H.sub.2O 0.1% HCl/acetonitrile: 90/10 to 5/95). The product 3a is then obtained in the form of a beige oil (45 mg, 20% calculated for the trifluoroacetate salt).

(53) .sup.1H NMR (500 MHz, D.sub.2O): δ 8.56-8.53 (t, 1H), 8.29-8.28 (d, 1H), 8.13-8.11 (d, 1H), 7.96-7.93 (t, 1H), 7.60-7.58 (d, 1H), 7.45-7.44 (d, 1H), 4.92 (s, 2H), 4.79 (s, 2H), 4.57 (s, 2H), 4.15 (s, 2H), 3.87-3.84 (m, 4H), 3.40 (br s, 4H), 3.20-3.18 (t, 2H)

(54) .sup.13C NMR (125 MHz, D.sub.2O): δ 166.68, 160.01, 156.08, 152.05, 149.33, 148.24, 143.26, 130.80, 129.02, 128.23, 128.13, 63.22, 61.62, 59.12, 56.66, 51.68, 46.08

(55) ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.20H.sub.26N.sub.5O.sub.2].sup.2+ 368.2081, obtained 368.2078; [M+H].sup.+, calculated for [C.sub.20H.sub.26N.sub.5O.sub.2].sup.2+ 184.6076, obtained 184.6078 [M+2H].sup.2+.

(56) Analytical C-18 HPLC (H.sub.2O 0.1% TFA/ACN 0.1% TFA 98/2>20/80): t.sub.R: 18.42 min m/z calculated for [C.sub.20H.sub.26N.sub.5O.sub.2].sup.+ 368.21; obtained 368.25 [M+H].sup.+; purity: 91%

(57) During the purification of the compound 3a, the compound 13a is also obtained in the form of a beige oil (9.8 mg).

(58) .sup.1H NMR (500 MHz, D.sub.2O): δ 8.51 (t, J=8.0 Hz, 1H), 8.05 (d, J=7.9 Hz, 1H), 7.98 (t, J=7.8 Hz, 1H), 7.90 (d, J=8.0 Hz, 1H), 7.60 (d, J=7.6 Hz, 1H), 7.49 (d, J=7.9 Hz, 1H), 5.03 (s, 2H), 4.90 (s, 2H), 4.46 (s, 2H), 4.07 (s, 2H), 3.91-3.74 (m, 4H), 3.44 (s, 4H), 3.10 (t, J=4.7 Hz, 2H).

(59) .sup.13C NMR (125 MHz, D.sub.2O): δ 161.14, 158.42, 155.42, 151.94, 149.29, 143.29, 128.99, 128.56, 127.54, 126.15, 63.51, 62.32, 61.60, 57.74, 56.68, 50.65

(60) ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.20H.sub.28N.sub.5O].sup.+ 354.228837, obtained 354.228823 [M+H].sup.+; calculated for [C.sub.20H.sub.29N.sub.5O].sup.2+ 177.618057, obtained 177.618215 [M+2H].sup.2+; calculated for [C.sub.13H.sub.19N.sub.4].sup.+ 231.160423, obtained 231.160338 [M-fragmentation].sup.+; calculated for [C.sub.20H.sub.27N.sub.5].sup.2+ 168.612774, obtained 168.612527 [M+2H—H.sub.2O].sup.2+; calculated for [C.sub.7H.sub.8N].sup.+ 106.065126, obtained 106.065011 [fragment].sup.+.

(61) Compound 3c—Hydrolysis Step

(62) The compound 10c (250.4 mg; 0.78 mmol) is solubilized in ultrapure HCl (3M; 4.8 ml). The reaction mixture s stirred at reflux for 20 h. After evaporation, an orange oil is obtained. This oil is then purified by C18-HPLC chromatography (H.sub.2O 0.1% TFA/acetonitrile 0.1% TFA: 98/2>20/80); the product 3c is then obtained in the form of a beige oil (97.9 mg, 25% calculated for the trifluoroacetate salt).

(63) .sup.1H NMR (500 MHz, D.sub.2O): δ 7.95-7.92 (t, 1H), 7.52-7.47 (2d, 2H), 4.80 (s, 2H), 4.28 (s, 2H), 3.89-3.84 (m, 6H), 3.57 (br s, 2H), 3.35 (m, 2H), 3.26-3.25 (m, 2H), 3.12-3.10 (m, 2H)

(64) .sup.13C NMR (125 MHz, D.sub.2O): δ 177.08, 160.30, 151.45, 143.16, 129.30, 127.70, 63.06, 62.91, 62.81, 58.04, 57.92, 57.25, 52.15, 49.98, 46.49.

(65) ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.15H.sub.23N.sub.4O.sub.2].sup.+ 291.181552, obtained 291.181585 [M+H].sup.+; calculated for [C.sub.15H.sub.24N.sub.4O.sub.2].sup.2+ 146.094414, obtained 146.094221 [M+2H].sup.2+.

(66) Analytical C-18 HPLC (H.sub.2O 0.1% TFA/ACN 0.1% TFA 98/2>20/80): t.sub.R: 16.57 min m/z calculated for [C.sub.15H.sub.23N.sub.4O.sub.2].sup.+ 291.18; obtained 291.25 [M+H].sup.+; purity: 98%

(67) Compound 11—Reducing Step C

(68) Under an inert atmosphere, a solution of trifluoroacetic acid (6.2713 g, 55 mmol) in anhydrous THF (10 ml) is slowly added to a suspension of NaBH (2.196 g, 58 mmol) in anhydrous THF (30 ml) cooled to 0° C. The pyclen oxalate (1 g, 3.84 mmol) solubilized in an anhydrous CH.sub.2Cl.sub.2/MeOH mixture (10 ml/50 μL) is then slowly added to the reaction medium, at 0° C. with vigorous stirring. The mixture is stirred at 0° C. for 30 min, then for two days at ambient temperature.

(69) The reaction medium is then filtered on sintered glass of porosity 4, and a solution of NaOH (10 M; 10 ml) is added to the filtrate. After vigorous stirring of the two-phase mixture for 5 min at AT, 40 ml of ultrapure water and 100 ml of DCM are added; the desired product is extracted in the organic phase with 3×100 ml of DCM. The organic phases are combined, dried over MgSO.sub.4, filtered and evaporated off to give the crude product (white foam; 875.6 mg).

(70) The crude product (642.3 mg) is purified on a short column of basic alumina (Ø3 cm; 5 cm) with a DCM/MeOH gradient (100/0.fwdarw.85/15) so as to give the compound 11 in boron salt form (white crystals; 208.7 mg; 21% (calculated for 2 BH.sub.3)).

(71) FIG. 7 gives the structure obtained by X-ray diffraction of the compound 11, and proves that its formula is the following:

(72) ##STR00038##

(73) ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.13H.sub.21N.sub.4].sup.+: 233.176073 m/z; found: 233.175875 [M+H].sup.+

(74) .sup.1H NMR (500 MHz, CDCl.sub.3): δ 7.72 (t, J=7.7 Hz, 1H), 7.27 (2d, J=7.0, 3.1 Hz, 2H), 5.71 (s, 1H), 4.49 (td, J=11.4, 4.7 Hz, 1H), 4.35 (dd, J=14.5, 8.4 Hz, 2H), 4.20 (d, J=14.5 Hz, 1H), 3.69 (dd, J=14.5, 10.4 Hz, 2H), 3.55-3.41 (m, 1H), 3.41-3.30 (m, 1H), 3.22-3.10 (m, 1H), 2.82 (dd, J=14.7, 6.7 Hz, 2H), 2.61 (dd, J=14.8, 5.3 Hz, 1H), 2.47 (d, J=14.2 Hz, 1H), 2.25 (td, J=12.4, 2.6 Hz, 1H), 2.03 (dd, J=19.4, 11.1 Hz, 2H), 0.86 (td, J=11.3, 7.3 Hz, 1H).

(75) .sup.1H NMR (125 MHz, CDCl.sub.3): δ 154.56, 153.19, 138.09, 125.13, 123.95, 69.37, 62.67, 62.48, 61.14, 60.79, 60.52, 53.55, 52.23, 50.78, 47.04, 44.76.

(76) Compound 4—Hydrolysis Step

(77) A solution of ultrapure hydrochloric acid (3M, 2.2 ml) is added to the compound 11 in order to hydrolyze the amino-borane bonds. The acid mixture obtained is brought to 40′C for 3 days. NaOH pellets are added in order to adjust the pH to 12-14. The aqueous phase is extracted with dichloromethane (3×25 ml) and the organic phase is dried over MgSO.sub.4, filtered and concentrated. The compound 4 obtained is a yellow solid (90 mg, 100%).

(78) .sup.1H NMR (500 MHz, CDCl.sub.3): δ 7.57 (t, J=7.6 Hz, 1H), 7.10 (dd, J=7.3, 5.3 Hz, 2H), 4.19 (s, 2H), 3.97 (s, 2H), 3.35-3.25 (m, 2H), 3.07 (d, J=10.7 Hz, 2H), 2.87 (d, J=4.4 Hz, 2H), 2.73 (d, J=2.6 Hz, 2H), 2.37 (s, 2H).

(79) .sup.13C NMR (125 MHz, CDCl.sub.3): δ 160.98, 160.00, 137.12, 122.42, 122.31, 61.97, 55.80, 54.57, 49.61, 45.87, 43.15.

Example 2: Preparation of Complexes According to the Invention

Preparation of the [Mn(2a)](ClO.SUB.4.) Complex

(80) The compound 3a.3HCl (20 mg, 0.044 mmol) is dissolved in water (5 ml) and the pH of the solution is adjusted to 5 with a 1M KOH solution. A solution of Mn(ClO.sub.4).sub.2.6H.sub.2O (16 mg, 0.044 mmol) in water (2 ml) is added to the ligand solution. The reaction medium is brought to reflux for 1 h and is then concentrated.

(81) FIG. 8 gives the structure obtained by X-ray diffraction of the [Mn(2a)](ClO.sub.4) complex. ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.18H.sub.22MnN.sub.5O.sub.2].sup.+ 395.114846, obtained 395.114156; calculated for [C.sub.18H.sub.23MnN.sub.5O.sub.2].sup.2+ 198.061061, obtained 198.061026.

Preparation of the [Zn(2a)](ClO.SUB.4.) Complex

(82) The compound 3a.3HCl (20 mg, 0.044 mmol) is dissolved in water (5 ml) and the pH of the solution is adjusted to 5 with a 1M KOH solution. A solution of Zn(ClO.sub.4).sub.2.6H.sub.2O (16.5 mg, 0.044 mmol) in water (2 ml) is added to the ligand solution. The reaction medium is brought to reflux for 1 h and is then concentrated.

(83) ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.18H.sub.22ZnN.sub.5O].sup.+ 404.105944, obtained 404.106289; calculated for [C.sub.18H.sub.23ZnN.sub.5O.sub.2].sup.2+ 202.556610, obtained 202.557059.

Preparation of the [Cu(2a)](ClO.SUB.4.) Complex

(84) The compound 3a.3HCl (20 mg, 0.044 mmol) is dissolved in water (5 ml) and the pH of the solution is adjusted to 5 with a 1M KOH solution. A solution of Cu(ClO.sub.4).sub.2.6H.sub.2O (16.4 mg, 0.044 mmol) in water (2 ml) is added to the ligand solution. The reaction medium is brought to reflux for 1 h and is then concentrated.

(85) ESI-HR-MS (positive, H.sub.2O): m/z calculated for [C.sub.18H.sub.22CuN.sub.5O.sub.2].sup.+ 403.106399, obtained 403.106320; calculated for [C.sub.18H.sub.23CuN.sub.5O.sub.2].sup.2+ 202.056838, obtained 202.056983.

Preparation of the [Zn(3a)](Cl) Complex

(86) In a G10 glass vessel, under an argon stream, a solution of ZnCl.sub.2 (11.58 mg; 0.085 mmol) in anhydrous 1-butanol (1 ml) is added to a solution of the compound 3a (8.2 mg; 0.017 mmol) in the same solvent (1 ml) in the presence of DIPEA (5.9 μL; 0.034 mmol). The mixture is then stirred with microwaves at 130′C for 8 h. After returning to AT, all of the reaction medium is transferred into a 50 ml Falcon™ tube and centrifuged at 4000 g for 12 min. The supernatant is removed and the precipitate is rinsed with THF (2×5 ml) by centrifugation. The precipitate is solubilized in water and evaporated to give the expected complex in the form of a beige powder (4.5 mg; 57%).

(87) Maldi-MS (ditranol, HCCA/H.sub.2O 1:1): for C.sub.20H.sub.24N.sub.5O.sub.2Zn.sup.+ m/z obtained: 430.30, m/z calculated: 430.12 [M].sup.+; for C.sub.20H.sub.26N.sub.5O.sub.3Zn.sup.+ m/z obtained: 448.30, m/z calculated: 448.13 [M+H.sub.2O].sup.+

Preparation of the [Cu(3a)](ClO.SUB.4.) Complex

(88) In a G10 glass vessel, under an argon stream, a solution of Cu(ClO.sub.4).sub.2.6H.sub.2O (50 mg; 0.12 mmol) in anhydrous 1-butanol (1.3 ml) is added to a solution of the compound 3a (13.3 mg; 0.027 mmol) in the same solvent (1.4 ml) in the presence of DIPEA (9.4 μl; 0.054 mmol). The mixture is then stirred with microwaves at 130° C. for 8 h. After returning to AT, all of the reaction medium is transferred into a 50 ml Falcon™ tube and centrifuged at 4000 g for 12 min. The supernatant is removed and the precipitate is rinsed with THF (2×5 ml) by centrifugation. The precipitate is solubilized in water and slowly evaporated to give the expected complex in the form of blue needles (12.8 mg; 89%).

(89) ESI-MS (positive, H.sub.2O/ACN 50/50 0.1% TFA): for C.sub.20H.sub.24N.sub.5O.sub.2Cu m/z obtained: 429.05, m/z calculated: 429.12 [M].sup.+; for C.sub.20H.sub.25N.sub.5O.sub.2Cu.sup.2+ m/z obtained: 215.10, m/z calculated: 215.06 [M+H].sup.2+; for C.sub.22H.sub.25F.sub.3N.sub.5O.sub.4Cu.sup.+

(90) UV: the UV analysis shows an absorbance characteristic of a d.fwdarw.d transition of the Cu.sup.2+ of the complex at λ.sub.max=650 nm with a molar absorption coefficient ε=103 l.Math.mol.sup.−1.Math.cm.sup.−1.

Preparation of the [Mn(3a)](ClO.SUB.4.) Complex

(91) In a G10 glass vessel, under an argon stream, a solution of Mn(ClO.sub.4).sub.2.6H.sub.2O (44.4 mg; 0.175 mmol) in anhydrous 1-butanol (1.7 ml) is added to a solution of the compound 3a (14.6 mg; 0.035 mmol) in the same solvent (1.8 ml) in the presence of DIPEA (12.2 μl; 0.07 mmol). The mixture is stirred with microwaves at 130° C. for 8 h. After returning to AT, all of the reaction medium is transferred into a 50 ml Falcon™ and centrifuged at 4000 g for 12 min. The supernatant is removed and the precipitate is rinsed with THF (2×5 ml) by centrifugation. The precipitate is solubilized in water and evaporated to give the expected complex in the form of an orange powder (4.5 mg; 25%).

(92) Maldi-MS (ditranol, HCCA/H.sub.2O 1:1): for C.sub.20H.sub.26MnN.sub.5O.sub.3.sup.+ m/z obtained: 439.506, m/z calculated: 439.141 [M+H.sub.2O].sup.+