Formic Acid → Penciclovir

Participants

Reaction Steps

A solution of 4-(2-amino-6-chloropurin-9-yl)-2-benzyloxymethylbutyl benzyl ether (0.904 g, 2 mmol) in 25 ml of 80% aqueous formic acid was kept at 100° C. for 1h, palladium catalyst (10% on carbon, 0.40 g) was added, and the mixture was hydrogenated at room temperature and atmospheric pressure with efficient stirring for 45 min. After evaporation in vacuum to dryness the residue was heated to boiling with 50 ml of water, 1 ml of concentrated aqueous ammonia was added, the solution was boiled gently for a short while and then evaporated to dryness. Recrystallization from water afforded 0.23 g (45%) of 9-[4-hydroxy-3-(hydroxymethyl)butyl]guanine. M.p. 252°-262° C. (decomposition, slow heating) or 264°-265° (fast immersion of the capillary).

Provenance & Evidence