DI- AND TRIPHOSPHATE PRODRUGS

Abstract

Compounds which can be used as prodrugs, in particular nucleoside diphosphate and triphosphate prodrugs, and a method for producing these compounds. The aim is to provide improved di- and/or triphosphate prodrugs, in particular nucleotide or nucleotide analog prodrugs. This is achieved in one aspect by providing bioreversibly and asymmetrically masked di- and triphosphate compounds, in particular nucleoside diphosphate and nucleoside triphosphate compounds or the analogs thereof. The masking only occurs at the terminal phosphate, i.e. at the β- or γ-phosphate, whereas the masking of the internal phosphate is omitted.

Claims

1. A compound having general formula I ##STR00033## or a pharmaceutically acceptable salt thereof, wherein R.sup.1, R.sup.3, R.sup.5 and R.sup.7 are independently H, halogen, NO.sub.2, CN, SO.sub.3H, a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, or a substituted or unsubstituted aromatic or heteroaromatic radical, R.sup.2 and R.sup.4 are independently H or Z—C(Y)—R.sub.A, but are not both H, R.sup.6 and R.sup.8 are independently H, Z—C(Y)—R.sub.B, but are not both H, Z, Y is independently O, S or HN, R.sub.A and R.sub.B are different and each is a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, or a substituted or unsubstituted aromatic or heteroaromatic radical, R.sup.9 is nucleoside, nucleoside monophosphate, nucleoside analogue, nucleoside monophosphate analogue, O—R.sup.10, OP(O)(OH)—R.sup.10 or OP(O)(OH)—O—R.sup.10, wherein R.sup.10 is a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, or a substituted or unsubstituted aromatic or heteroaromatic radical, R.sup.12, R.sup.13, R.sup.14 and R.sup.15 are independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, a substituted or unsubstituted aromatic or heteroaromatic radical, and/or an electron acceptor.

2. The compound according to claim 1, wherein a) R.sup.1, R.sup.3, R.sup.5 and R.sup.7 i. are each independently H, halogen, NO.sub.2, CN, SO.sub.3H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, or ii. are each independently H, halogen, NO.sub.2, CN, SO.sub.3H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-10-aliphatic radical or C.sub.1-10-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. are each independently selected from the group consisting of H, halogen, NO.sub.2, CN, SO.sub.3H, substituted or unsubstituted C.sub.1-20-alkyl, substituted or unsubstituted C.sub.2-20-alkenyl, substituted or unsubstituted C.sub.2-20-alkinyl, substituted or unsubstituted C.sub.4-20-alkeninyl, substituted or unsubstituted C.sub.3-20-cycloalkyl, substituted or unsubstituted C.sub.3-20-cycloalkenyl, substituted or unsubstituted C.sub.5-20-cycloalkinyl, substituted or unsubstituted C.sub.5-20-cycloalkeninyl, substituted or unsubstituted C.sub.1-20-heteroalkyl, substituted or unsubstituted C.sub.2-20-heteroalkenyl, substituted or unsubstituted C.sub.2-20-heteroalkinyl, substituted or unsubstituted C.sub.4-20-heteroalkeninyl, substituted or unsubstituted C.sub.5-24-aryl, substituted or unsubstituted C.sub.3-24-heteroaryl, or iv. are each independently selected from the group consisting of H, halogen, NO.sub.2, CN, SO.sub.3H, substituted or unsubstituted C.sub.1-10-alkyl, substituted or unsubstituted C.sub.2-10-alkenyl, substituted or unsubstituted C.sub.2-10-alkinyl, substituted or unsubstituted C.sub.4-10-alkeninyl, substituted or unsubstituted C.sub.3-10-cycloalkyl, substituted or unsubstituted C.sub.3-10-cycloalkenyl, substituted or unsubstituted C.sub.5-10-cycloalkinyl, substituted or unsubstituted C.sub.5-10-cycloalkeninyl, substituted or unsubstituted C.sub.1-10-heteroalkyl, substituted or unsubstituted C.sub.2-10-heteroalkenyl, substituted or unsubstituted C.sub.2-10-heteroalkinyl, substituted or unsubstituted C.sub.4-10-heteroalkeninyl, substituted or unsubstituted C.sub.5-12-aryl, substituted or unsubstituted C.sub.3-12-heteroaryl, or v. are all H, b) R.sub.A and R.sub.B are different and i. are each independently a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, or ii. are each independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-10-aliphatic radical or C.sub.1-10-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. are each independently selected from the group consisting of substituted or unsubstituted C.sub.1-20-alkyl, substituted or unsubstituted C.sub.2-20-alkenyl, substituted or unsubstituted C.sub.2-20-alkinyl, substituted or unsubstituted C.sub.4-20-alkeninyl, substituted or unsubstituted C.sub.3-20-cycloalkyl, substituted or unsubstituted C.sub.3-20-cycloalkenyl, substituted or unsubstituted C.sub.5-20-cycloalkinyl, substituted or unsubstituted C.sub.5-20-cycloalkeninyl, substituted or unsubstituted C.sub.1-20-heteroalkyl, substituted or unsubstituted C.sub.2-20-heteroalkenyl, substituted or unsubstituted C.sub.2-20-heteroalkinyl, substituted or unsubstituted C.sub.4-20-heteroalkeninyl, substituted or unsubstituted C.sub.5-24-aryl, substituted or unsubstituted C.sub.3-24-heteroaryl, preferably C.sub.1-20-Alkyl or C.sub.1-20-alkenyl, c) R.sup.10 i. is a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, or ii. is a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-10-aliphatic radical or C.sub.1-10-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. is a C.sub.1-20-alkyl or C.sub.1-20-alkenyl or a sugar radical, and d) R.sup.12, R.sup.13, R.sup.14 and R.sup.15 i. are each independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, and/or an electron acceptor sind, or ii. are each independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-10-aliphatic radical or C.sub.1-10-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. are each independently selected from the group consisting of H, substituted or unsubstituted C.sub.1-20-alkyl, substituted or unsubstituted C.sub.2-20-alkenyl, substituted or unsubstituted C.sub.2-20-alkinyl, substituted or unsubstituted C.sub.4-20-alkeninyl, substituted or unsubstituted C.sub.3-20-cycloalkyl, substituted or unsubstituted C.sub.3-20-cycloalkenyl, substituted or unsubstituted C.sub.5-20-cycloalkinyl, substituted or unsubstituted C.sub.5-20-cycloalkeninyl, substituted or unsubstituted C.sub.1-20-heteroalkyl, substituted or unsubstituted C.sub.2-20-heteroalkenyl, substituted or unsubstituted C.sub.2-20-heteroalkinyl, substituted or unsubstituted C.sub.4-20-heteroalkeninyl, substituted or unsubstituted C.sub.5-24-aryl, substituted or unsubstituted C.sub.3-24-heteroaryl, or iv. are each independently selected from the group consisting of H, substituted or unsubstituted C.sub.1-10-alkyl, substituted or unsubstituted C.sub.2-10-alkenyl, substituted or unsubstituted C.sub.2-10-alkinyl, substituted or unsubstituted C.sub.4-10-alkeninyl, substituted or unsubstituted C.sub.3-10-cycloalkyl, substituted or unsubstituted C.sub.3-10-cycloalkenyl, substituted or unsubstituted C.sub.5-10-cycloalkinyl, substituted or unsubstituted C.sub.5-10-cycloalkeninyl, substituted or unsubstituted C.sub.1-10-heteroalkyl, substituted or unsubstituted C.sub.2-10-heteroalkenyl, substituted or unsubstituted C.sub.2-10-heteroalkinyl, substituted or unsubstituted C.sub.4-10-heteroalkeninyl, substituted or unsubstituted C.sub.5-12-aryl, substituted or unsubstituted C.sub.3-12-heteroaryl, or v. are all H, or vi. are an electron acceptor or H, providing that R.sup.12 and R.sup.14 are each H and R.sup.13 and R.sup.15 are each an electron acceptor, or R.sup.13 and R.sup.15 are each H and R.sup.12 and R.sup.14 are each an electron acceptor.

3. The compound according to claim 1, wherein compound I is a compound according to the following formula Id ##STR00034## or is a pharmaceutically acceptable salt thereof, and wherein Z═O, S or HN, is preferably O.

4. A medicinal product comprising as active ingredient a compound according to claim 1.

5. An antiviral medicinal product comprising as active ingredient a compound according to claim 1.

6. A pharmaceutical composition, comprising a compound according to claim 1 and a pharmaceutically acceptable carrier.

7. A method for producing a compound having general formula I ##STR00035## or a pharmaceutically acceptable salt thereof, wherein R.sup.1, R.sup.3, R.sup.5 and R.sup.7 are independently H, halogen, NO.sub.2, CN, SO.sub.3H, a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, or a substituted or unsubstituted aromatic or heteroaromatic radical, R.sup.2 and R.sup.4 are independently H or Z—C(Y)—R.sub.A, but are not both H, R.sup.6 and R.sup.8 are independently H, Z—C(Y)—R.sub.B, but are not both H, Z, Y is independently O, S or HN, R.sub.A and R.sub.B are different and each is a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, or a substituted or unsubstituted aromatic or heteroaromatic radical, R.sup.9 is nucleoside, nucleoside monophosphate, nucleoside analogue, nucleoside monophosphate analogue, O—R.sup.10, OP(O)(OH)—R.sup.10 or OP(O)(OH)—O—R.sup.10, wherein R.sup.10 is a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, or a substituted or unsubstituted aromatic or heteroaromatic radical, and wherein R.sup.12, R.sup.13, R.sup.14 and R.sup.15 are independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched aliphatic or heteroaliphatic radical, a substituted or unsubstituted aromatic or heteroaromatic radical, and/or an electron acceptor, comprising the following steps: a.sub.1) reacting a compound having general formula II.sub.A ##STR00036## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.12 and R.sup.13 are defined as above, with i) phosphorus trichloride PCl.sub.3 and N,N-diisopropylamine, or ii) bis(N,N-diisopropylamino)chlorophosphine to synthesise a compound having general formula III ##STR00037## b.sub.1) reacting the compound having formula III obtained in a) with a compound having general formula II.sub.B ##STR00038## wherein R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.14 and R.sup.15 are defined as above, to synthesise a compound having general formula IV ##STR00039## c.sub.1) reacting the compound having formula IV obtained in b) with a compound according to general formula V ##STR00040## wherein R.sup.9 is defined as above, or a.sub.2) reacting a compound having general formula II.sub.A ##STR00041## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.12, and R.sup.13 are defined as above, with diphenylphosphonate to synthesise a compound having general VI ##STR00042## b.sub.2) reacting the compound with formula VI obtained in a) with a compound having general formula II.sub.B ##STR00043## wherein R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.14 and R.sup.15 are defined as above, to synthesise a compound having general formula VII ##STR00044## c.sub.2) reacting the compound with formula VII obtained in b) with i) a compound according to general formula V ##STR00045## or ii) with phosphoric acid or a phosphoric acid salt and R.sup.9 or a compound comprising R.sup.9, wherein R.sup.9 is defined as above.

8. The method according to claim 7, wherein a) R.sup.1, R.sup.3, R.sup.5 and R.sup.7 i. are each independently H, halogen, NO.sub.2, CN, SO.sub.3H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, or ii. are each independently H, halogen, NO.sub.2, CN, SO.sub.3H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. are each independently selected from the group consisting of H, halogen, NO.sub.2, CN, SO.sub.3H, substituted or unsubstituted C.sub.1-20-alkyl, substituted or unsubstituted C.sub.2-20-alkenyl, substituted or unsubstituted C.sub.2-20-alkinyl, substituted or unsubstituted C.sub.4-20-alkeninyl, substituted or unsubstituted C.sub.3-20-cycloalkyl, substituted or unsubstituted C.sub.3-20-cycloalkenyl, substituted or unsubstituted C.sub.5-20-cycloalkinyl, substituted or unsubstituted C.sub.5-20-cycloalkeninyl, substituted or unsubstituted C.sub.1-20-heteroalkyl, substituted or unsubstituted C.sub.2-20-heteroalkenyl, substituted or unsubstituted C.sub.2-20-heteroalkinyl, substituted or unsubstituted C.sub.4-20-heteroalkeninyl, substituted or unsubstituted C.sub.5-24-aryl, substituted or unsubstituted C.sub.3-24-heteroaryl, or iv. are each independently selected from the group consisting of H, halogen, NO.sub.2, CN, SO.sub.3H, substituted or unsubstituted C.sub.1-10-alkyl, substituted or unsubstituted C.sub.2-10-alkenyl, substituted or unsubstituted C.sub.2-10-alkinyl, substituted or unsubstituted C.sub.4-10-alkeninyl, substituted or unsubstituted C.sub.3-10-cycloalkyl, substituted or unsubstituted C.sub.3-10-cycloalkenyl, substituted or unsubstituted C.sub.5-10-cycloalkinyl, substituted or unsubstituted C.sub.5-10-cycloalkeninyl, substituted or unsubstituted C.sub.1-10-heteroalkyl, substituted or unsubstituted C.sub.2-10-heteroalkenyl, substituted or unsubstituted C.sub.2-10-heteroalkinyl, substituted or unsubstituted C.sub.4-10-heteroalkeninyl, substituted or unsubstituted C.sub.5-12-aryl, substituted or unsubstituted C.sub.3-12-heteroaryl, or v. are all H, b) R.sub.A and R.sub.B are different and i. are each independently a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, or ii. are each independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-10-aliphatic radical or C.sub.1-10-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. are each independently selected from the group consisting of substituted or unsubstituted C.sub.1-20-alkyl, substituted or unsubstituted C.sub.2-20-alkenyl, substituted or unsubstituted C.sub.2-20-alkinyl, substituted or unsubstituted C.sub.4-20-alkeninyl, substituted or unsubstituted C.sub.3-20-cycloalkyl, substituted or unsubstituted C.sub.3-20-cycloalkenyl, substituted or unsubstituted C.sub.5-20-cycloalkinyl, substituted or unsubstituted C.sub.5-20-cycloalkeninyl, substituted or unsubstituted C.sub.1-20-heteroalkyl, substituted or unsubstituted C.sub.2-20-heteroalkenyl, substituted or unsubstituted C.sub.2-20-heteroalkinyl, substituted or unsubstituted C.sub.4-20-heteroalkeninyl, substituted or unsubstituted C.sub.5-24-aryl, substituted or unsubstituted C.sub.3-24-heteroaryl, preferably C.sub.1-20-Alkyl or C.sub.1-20-alkenyl, c) R.sup.10 i. is a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, or ii. is a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-10-aliphatic radical or C.sub.1-10-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. is a C.sub.1-20-alkyl or C.sub.1-20-alkenyl or a sugar radical, and d) R.sup.12, R.sup.3, R.sup.14 and R.sup.15 i. are each independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, a substituted or unsubstituted C.sub.5-20-aromatic radical or C.sub.3-20-heteroaromatic radical, and/or an electron acceptor, or ii. are each independently H, a substituted or unsubstituted cyclic, acyclic, linear or branched C.sub.1-20-aliphatic radical or C.sub.1-20-heteroaliphatic radical, or a substituted or unsubstituted C.sub.5-12-aromatic radical or C.sub.3-12-heteroaromatic radical, or iii. are each independently selected from the group consisting of H, substituted or unsubstituted C.sub.1-20-alkyl, substituted or unsubstituted C.sub.2-20-alkenyl, substituted or unsubstituted C.sub.2-20-alkinyl, substituted or unsubstituted C.sub.4-20-alkeninyl, substituted or unsubstituted C.sub.3-20-cycloalkyl, substituted or unsubstituted C.sub.3-20-cycloalkenyl, substituted or unsubstituted C.sub.5-20-cycloalkinyl, substituted or unsubstituted C.sub.5-20-cycloalkeninyl, substituted or unsubstituted C.sub.1-20-heteroalkyl, substituted or unsubstituted C.sub.2-20-heteroalkenyl, substituted or unsubstituted C.sub.2-20-heteroalkinyl, substituted or unsubstituted C.sub.4-20-heteroalkeninyl, substituted or unsubstituted C.sub.5-24-aryl, substituted or unsubstituted C.sub.3-24-heteroaryl, or iv. are each independently selected from the group consisting of H, substituted or unsubstituted C.sub.1-10-alkyl, substituted or unsubstituted C.sub.2-10-alkenyl, substituted or unsubstituted C.sub.2-10-alkinyl, substituted or unsubstituted C.sub.4-10-alkeninyl, substituted or unsubstituted C.sub.3-10-cycloalkyl, substituted or unsubstituted C.sub.3-10-cycloalkenyl, substituted or unsubstituted C.sub.5-10-cycloalkinyl, substituted or unsubstituted C.sub.5-10-cycloalkeninyl, substituted or unsubstituted C.sub.1-10-heteroalkyl, substituted or unsubstituted C.sub.2-10-heteroalkenyl, substituted or unsubstituted C.sub.2-10-heteroalkinyl, substituted or unsubstituted C.sub.4-10-heteroalkeninyl, substituted or unsubstituted C.sub.5-12-aryl, substituted or unsubstituted C.sub.3-12-heteroaryl, or v. are all H, or vi. are an electron acceptor or H, providing that R.sup.12 and R.sup.14 are each H and R.sup.13 and R.sup.15 are each an electron acceptor, or R.sup.13 and R.sup.15 are each H and R.sup.12 and R.sup.14 are each an electron acceptor.

9. An antiretroviral medicinal product comprising as active ingredient a compound according to claim 1.

10. The antiretroviral medicinal product according to claim 9, wherein the medicinal product is for the treatment of an HIV-infection, hepatitis-infection, influenza or haemorrhagic fever.

Description

[0103] In the following, the invention will be explained in greater detail with reference to FIG. 1 and examples intended solely for illustrative purposes. In the drawing:

[0104] FIG. 1 is a schematic representation of the intracellular cleavage of the masks in an embodiment of the compound according to the invention.

[0105] FIG. 1 is a schematic representation of the assumed course of the release of a nucleosidediphosphate prodrug (NDP prodrug) according to an embodiment of the present invention in the cell. The two otherwise negatively charged oxygen atoms (shown in bold) of the hydroxyl groups of the terminal phosphate (in this case the β-phosphorus atom) are substituted asymmetrically in the NDP prodrug, i.e. masked with two different masks A and B (here different acyloxybenzyl derivatives). For this purpose, the radicals R.sub.A and R.sub.B differ with regard to their stability and lipophilicity. Radical R.sub.A is less stable than radical R.sub.B, radical R.sub.B is more lipophilic than radical R.sub.A. In the cell, the relatively unstable mask A is removed quickly following a rapidly completed enzymatic attack on the ester group by esterases (E) present in the cell and its subsequent spontaneous decomposition, resulting in a monomasked intermediate product. A nucleophilic attack (Nu=nucleophil) on the phosphorus anhydride bond with cleaving thereof does not occur, so the undesirable formation of the monophosphate is prevented. Mask B is also cleaved by the same mechanisms as mask A, but in a slower process, so that the unmasked nucleosidediphosphate prodrug is finally released in the cell.

EXAMPLES

[0106] A general schema for an embodiment of a method according to the invention for producing compounds I according to the invention is reproduced in the following. A first benzyl alcohol derivative II.sub.A is brought into reaction with phosphorus trichloride (PCl.sub.3) to produce compound 100, which is reacted with N,N-diisopropylamine (NH(iPr).sub.2) to yield the corresponding phosphordiamidite compound III. Compound III is then brought to reaction with a second benzyl alcohol derivative II.sub.B in order to synthesise the phosphorodiamidite compound IV. This can then be coupled with a mono- or diphosphate compound V, a nucleoside monophosphate or nucleoside monophosphate analogue for example, either of which may optionally be denoted with the abbreviation NMP, or nucleoside diphosphate or nucleoside diphosphate analogue, which may optionally be denoted here with the abbreviation NDP, to yield compound I. NDP or NTP compounds according to the invention (including compounds containing nucleoside analogues) may also be denoted here optionally with the abbreviations DiPPro nucleotides or TriPPPro nucleotides.

##STR00020## ##STR00021##

[0107] In order to prepare phosphorodiamidite compound III, as an alternative the benzyl alcohol derivative II.sub.A can also be brought into reaction with bis(N,N-diisopropylamino)chlorophosphine according to the following general schema rather than with phosphorus trichloride (PCl.sub.3) and N, N-diisopropylamine.

##STR00022##

[0108] A general schema of an alternative embodiment of a method according to the invention for producing compounds I according to the invention is reproduced below.

##STR00023##

[0109] A first benzyl alcohol derivative II.sub.A is brought into reaction with diphenyl phosphonate (DPP) to produce compound VI, which is brought into reaction with a second benzyl alcohol derivative II.sub.B to synthesise the phosphonate compound VII. This may then be coupled with a mono- or diphosphate compound V, or first with phosphoric acid or a phosphoric acid salt and then with a R.sup.9 compound or a compound containing R.sup.9, a nucleoside monophosphate for example, so that compound I is obtained. A particular advantage of the last variant of this embodiment of the method according to the invention is triphosphate compounds can then be synthesised with the corresponding monophosphates, e.g., nucleoside monophosphates or analogues thereof.

[0110] Examples of DiPPro nucleotides produced in the method according to the invention are listed below:

[0111] a) Stavudine (d4T) as nucleoside analogue radical (Ph=phenyl; Me=methyl, OAc=acetoxy):

TABLE-US-00001 [00024] R.sub.A R.sub.B CH.sub.3 PhCF.sub.3 CH.sub.3 Ph—Me CH.sub.3 C.sub.7H.sub.15 CH.sub.3 C.sub.9H.sub.19 CH.sub.3 C.sub.11H.sub.23 (CH.sub.2).sub.3CH.sub.3 PhCF.sub.3 (CH.sub.2).sub.3CH.sub.3 Ph—Me (CH.sub.2).sub.3CH.sub.3 C.sub.7H.sub.15 (CH.sub.2).sub.3CH.sub.3 C.sub.9H.sub.19 (CH.sub.2).sub.3CH.sub.3 C.sub.11H.sub.23

[0112] b) Zidovudine (AZT) as nucleoside analogue radical:

TABLE-US-00002 [00025] R.sub.A R.sub.B CH.sub.3 PhCF.sub.3 CH.sub.3 C.sub.7H.sub.15 CH.sub.3 C.sub.9H.sub.19 CH.sub.3 C.sub.11H.sub.23 (CH.sub.2).sub.3CH.sub.3 PhCF.sub.3 (CH.sub.2).sub.3CH.sub.3 C.sub.7H.sub.15 (CH.sub.2).sub.3CH.sub.3 C.sub.9H.sub.19 (CH.sub.2).sub.3CH.sub.3 C.sub.11H.sub.23

[0113] 1. Production of Asymmetrically Masked Nucleoside Diphosphate and Nucleoside Triphosphate Compounds Using Phosphordiamidite Compounds

[0114] In order to produce asymmetrically masked nucleoside diphosphate or nucleosidetriphosphate compounds (DiPPro-, TriPPPro-nucleotides) according to the invention, first the respective asymmetrical phosphoramidites are prepared according to the general method described above, so that then a coupling can be made with the desired nucleotide (analogue) (nucleoside monophosphate or nucleoside diphosphate(analogue)) to form asymmetrical NDP or NTP. By this method, a large number of asymmetrically masked nucleosidediphosphate or nucleoside-triphosphate compounds were represented successfully with very good yields. The coupling of the asymmetrical phosphoramidites with the respective nucleoside monophosphates and nucleoside diphosphates was optimised in an acid-activated reaction, so that many combinations of nucleoside diphosphate or nucleoside triphosphate compounds can be accessed in quantitative conversions and high isolated yields.

[0115] 1.1 Synthesis of Phosphordiamidites

[0116] 1.1.1 Synthesis Path 1

##STR00026##

[0117] 1 equivalent phosphorus trichloride and 1 equivalent pyridine are dissolved in a large quantity of tetrahydrofuran (THF, approx. 20 mL/g PCl.sub.3) and cooled to −78° C. in a nitrogen atmosphere. 1 equivalent of the phenyl ester II.sub.Aa, also dissolved in THF, is added to this solution one drop at a time over a period of 1.5 h. After the addition by dripping, the cooler bath is removed, and the reaction mixture is stirred at room temperature (RT) for about 20 h until no more phenyl ester is detectable by TLC. Then 6.1 equivalents N,N-diisopropylamine are added one drop at a time at −10° C. After removal of the cooler bath, the reaction mixture is stirred at room temperature. When the intermediate compound 101 has been completely converted, i.e. after about 24 to 48 h, the salts formed are removed by filtration and then the solvent at reduced pressure. Without any further processing, product IIIa is purified on the Chromatotron® with benzine/triethylamine as the eluent.

1.1.2 Synthesis Path 2

[0118] ##STR00027##

[0119] 1 equivalent bis(N,N-diisopropylamino)-chlorophosphine is dissolved in diethylether or THF (12 mL/500 mg) in a nitrogen atmosphere. A solution of 2.1 equivalents triethylamine and 1.9 equivalents of the phenyl ester II.sub.Aa, in diethylether or THF (corresponding to 5 mL) is added slowly with ice cooling. Then the cooler bath is removed and the reaction mixture is stirred at room temperature. After 1 to 2 hours, the triethylammonium chloride formed is removed by filtration and finally the solvent at reduced pressure. Without any further processing, product IIIa is purified on the Chromatotron® with benzine/triethylamine as the eluent.

1.2 Synthesis of Phosphoramidites

[0120] ##STR00028##

[0121] 1.5 equivalents phosphordiamidite IIIa is first co-evaporated and finally dissolved in 2 mL/100 mg acetonitrile in a nitrogen atmosphere. A solution of 1 equivalent of the corresponding 4-acyloxybenzyl alcohol II.sub.Ba and 1 equivalent of a 0.25-molar 4,5-dicyanoimidazole activator solution in acetonitrile is added one drop at a time with ice cooling. After approx. 30 to 60 minutes stirring at room temperature, the reaction is ended by removing the solvent under reduced pressure. The residue is absorbed and filtered in benzine/triethylamine (9:1). The product IVa purified in the Chromatotron® with benzine/triethylamine as the eluent.

1.3 Synthesis of DiPPro-, TriPPPro-Nucleotides

[0122] ##STR00029##

[0123] The reaction is carried out in a nitrogen atmosphere. 1 equivalent of the corresponding N(C.sub.4H.sub.9).sub.4.sup.+ salt of the nucleoside monophosphate (NMP) or nucleosidediphosphate (NDP) is dissolved in acetonitrile (approx. 4 mL/100 g) and reacted with 1.5 equivalents of the phosphordiamidite IVa that was previously co-evaporated with acetonitrile. The phosphordiamidite IVa is activated by incremental addition of a 0.25 molar 4,5-dicyanoimidazole activator solution (in acetonitrile). 0.5 equivalents are added initially, and 0.25 equivalents are added every 5 min thereafter until complete conversion is achieved (not more than 1.75 equivalents). Oxidation is carried out by the addition of 1.5 equivalents of a 5.5 molar tBuOOH solution in n-decane. Reversed phase (RP) chromatography (“Puri Flash”), followed by ion exchange to form NH.sub.4.sup.+ and RP chromatography (Puri Flash) again, possibly several times, return the DiPPro-nucleotide or TriPPPro-nucleotide Ic in yields of up to 85%.

2. Production of Asymmetrically Masked Nucleoside Diphosphate and Nucleoside Triphosphate Compounds Using Phosphonate Compounds

2.1 Production of an Asymmetrically Substituted Phosphonate Compound

[0124] ##STR00030##

[0125] To synthesise the asymmetrically substituted phosphonate compound VIIa, 1 equivalent phenyl ester II.sub.Aa in pyridine (approx. 15 mL/g II.sub.A) is slowly added dropwise to a solution of 1,3 equivalents diphenyl phosphonate (DPP) in pyridine (approx. 20 mL/g DPP) that has been cooled to −5° C. in a nitrogen atmosphere. After stirring for ten minutes, 1,6 equivalents phenyl ester II.sub.Ba are added, and the solution is stirred for 2 h at 40° C. Then, all volatile components are removed at 40° C. in a high vacuum. The residue is also co-evaporated twice with toluene. Product VIIa is purified by chromatography with benzine/ethyl acetate/acetic acid as the eluent.

[0126] The resulting phosphonate compound VIIa may be brought into reaction with a nucleoside monophosphate or an analogue thereof to produce a nucleoside diphosphate or nucleoside diphosphate analogue (DiPPronucleotide(analogue)).

[0127] To produce nucleoside triphosphates (TriPPPro-nucleotides), first dibenzylpyrophosphate derivatives of compound VIIa are produced, and then the nucleoside triphosphate.

2.2 Production of Dibenzylpyrophosphate Derivatives of Compound VIIa

[0128] ##STR00031##

[0129] 1 equivalent phosphonate VIIa is dissolved in acetonitrile (approx. 10 mL/g phosphonate), if necessary with slight warming and reacted with 2 equivalents N-chlorosuccinimide (NCS) in a nitrogen atmosphere. After an hour, the solution is immediately added dropwise to 2,5 equivalents tetra-n-butylammonium monophosphate in acetonitrile (approx. 20 mL/g phosphate salt). The solution is stirred for 1 h and then separated from the solvent. The residue is absorbed in dichloromethane and cold 1 M ammonium acetate solution, and the phases are separated with the aid of a centrifuge. The organic phase is washed with cold water again, dried over sodium sulphate, filtered and finally separated from the solvent. The desired product Villa is extremely pure. Conversion is quantitative.

2.3 Production of TriPPPro-Nucleotides

[0130] ##STR00032##

[0131] The reaction is conducted in a nitrogen atmosphere. First, 5 equivalents trifluoroacetic acid anhydride (TFAA) and 8 equivalents triethylamine (TEA) are mixed in acetonitrile (ca. 20 mL/g TFAA) at 0° C. This solution is then added to 1 equivalent dibenzylpyrophosphate compound VIIIa in acetonitrile (approx. 20 mL/g dibenzyl pyrophosphate). After 10 min at 0° C., all volatile components are removed in a high vacuum. The residue is suspended in acetonitrile (approx. 20 mL/g dibenzyl pyrophosphate) and reacted with 5 equivalents TEA and 3 equivalents methylimidazole. After stirring for five minutes, 1 equivalent of the corresponding N(C.sub.4H.sub.9).sub.4.sup.+ salt of the nucleoside monophosphate (NMP, Nucl=nucleoside) dissolved in acetonitrile (approx. 20 mL/g NMP) is added, and the reaction is ended after 3 h by removal of the solvent at reduced pressure. Reversed phase (RP) chromatography (“Puri Flash”), followed by ion exchange to form NH.sub.4.sup.+ and RP chromatography (Puri Flash) again, possibly several times, return the TriPPPro-nucleotide Ie.sub.1 in yields of up to 50%.

3. Hydrolysis Studies

[0132] Hydrolysis studies in CEM/0 cell extract have provided some insights into the enzymatic release of nucleoside diphosphates from prodrugs. The samples are incubated in cell extract and stopped at various times. The analysis of the hydrolysis samples was carried out by High Performance Liquid (HPL) chromatography. In two different groups on the acyl units of the masks, the less stable one is cleaved quickly (e.g., R═CH.sub.3: t.sub.1/2=approx. 2 min; R═C.sub.4H.sub.9: t.sub.1/2=approx. 45 to 60 min), so that the more stable intermediate product forms. Then, the intermediate product hydrolyses quantitatively to the diphosphate. The formation of d4TDP was confirmed by co-injection of a d4TDP solution.

[0133] The chemical stability of the prodrugs was also tested in phosphate buffer at pH 7.3. For this purpose, solutions of the DiPPro and TriPPPro nucleotide are converted with a Sorensen type phosphate buffer (PBS), and the hydrolysis is monitored by HPL chromatography. The experiments show that all prodrugs are significantly more chemically stable than enzymatically stable (e.g., half-life periods of CH.sub.3/C.sub.9H.sub.19-DiPPro-d4TDP (decomposition of the prodrug): t.sub.1/2 (PBS)=48 h, t.sub.1/2(CEM/0)=2 min). Because of the greater stability, the formation of the nucleoside monophosphate can also be observed at the beginning of the hydrolysis in phosphate buffer. But since the selection of an asymmetrical mask combines a less stable group with a highly lipophilic group, the intermediate product (and the more stable) forms very quickly as in the cell extract, so that diphosphate formation is strongly favoured.