Patent ID: 6894159

Claim:
A process for preparing 2′-fluoro-5-methyl-β-L-arabino-furanosyluridine (L-FMAU) of formula (1), comprising: a) reacting a L-arabinose of formula (4) with a compound of formula (18) R—OH (18) to obtain a compound of formula (5), wherein R represents a benzyl, aryl or aralkyl group; b) condensing the compound of formula (5) with a compound of formula (19) H 3 CO—C(R 1 R 2 )—OCH 3 (19) to obtain the compound of formula (6); oxidizing the compound of formula (6) to obtain the compound of formula (7), reducing the compound of formula (7) to obtain the compound of formula (8), wherein R 1 and R 2 independently of one another represent hydrogen alkyl or aryl, and R represents a benzyl, aryl or aralkyl group; c) treating the compound of formula (8) with an acid to obtain the compound of formula (9); treating the compound of formula (9) with a compound of formula (18) R—OH (18) wherein R represents a benzyl, aryl or aralkyl group; in the presence of an acid to obtain the compound of formula (10); reacting and the compound of formula (10) with benzoyl chloride to obtain the compound of formula (11), which is then reacted with acetic acid and acetic anhydride in the presence of acid to obtain the compound of formula (12); d) converting the compound of formula (12) into the compound of formula (13); e) introducing a reactive leaving group into the compound of formula (13) to obtain the compound of formula (14), wherein L represents a reactive leaving group; f) fluorinating the compound of formula (14) to obtain the compound of formula (15); halogenating the compound of formula (15) to obtain the compound of formula (16); condensing the compound of formula (16) with thymine base to obtain the compound of formula (17), wherein Hal represents a halogen atom; and g) treating the compound of formula (17) with ammonia in methanol to produce the desired L-FMAU of formula (1).