Process for the production of purine derivatives and intermediates therefor
AssigneeNovartis International Pharmaceutical Ltd.
InventorsRichard Freer, Graham Richard Geen, Thomas Weir Ramsay, Andrew Colin Share, Neil Michael Smith
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Abstract
A process for preparing purine derivatives, such as famiciclovir and penciclovir, by reacting, in the presence of a palladium (0) catalyst and a ligand, a compound of the formula with a compound of the formula wherein X is H, OH or halo; Y is a leaving group; and R1 and R2 are selected independently from C1-12alkyl, aryl, C1-12alkylaryl, C1-12alkylsilyl, arylsilyl and C1-12alkyldiarylsilyl or are joined together to form a moiety of the formula wherein R3 and R4 are selected independently from H, C1-12alkyl and aryl.
Claims12
A process for the production of a compound of formula (I):
- wherein X is H, OH or halo;
- and R1 and R2 are selected independently from C1-12 alkyl, aryl, C1-2 alkylaryl, C1-12 alkylsilyl, arylsilyl and C1-12 alkyldiarylsilyl, or R1 and R2 are joined together to form a moiety of the formula:
- wherein R3 and R4 are selected independently from H, C1-12 alkyl and aryl, which method comprises reacting a compound of formula (II):
- wherein X is as defined for formula (I), with a compound of formula (III):
- wherein Y is a leaving group and R1 and R2 are as defined for formula (I), in the presence of a palladium(0) catalyst and a ligand.
A compound of formula (I):
- wherein X is H, OH or halo;
- and R1 and R2 are selected independently from C1-12 alkyl, aryl, C1-12 alkylaryl, C1-12 alkylsilyl, arylsilyl and C1-12 alkyldiarylsilyl, or R1 and R2 are joined together to form a moiety of the formula
- wherein R3 or R4 are selected independently from H, C1-12 alkyl and aryl.
A process for the preparation of a compound of formula (V):
- wherein X′ is H or OH and R5 and R6 are independently selected from H and R′CO wherein R′ is phenyl, or C1-18 alkyl, which process comprises producing a compound of formula (I) according to the process defined in claim 15, hydrogenating the compound of formula (I) hydrolyzing or hydrogenating —OR1 and —OR2 to form two hydroxy groups and thereafter if and as necessary:
- (i) acylating one or both of the hydroxy groups on the resulting 4-hydroxy-3-hydroxymethylbut-1-yl moiety to form compounds in which R5 and R6 represent R′CO;
- and/or
- (ii) hydrolyzing X=halogen to X′=OH.
Dependencies are inferred from the claim text.