Preparation of 2-amino-7-(1-substituted-2-hydroxyethyl)-3, 5-dihydropyrrolo[3,2-d]pyrimidin-4-ones

摘要

The compounds of formula I wherein Ar represents biaryl, carbocyclic or heterocyclic aryl, are prepared, as substantially pure enantiomers, by (a) condensing a compound of the formula as a substantially pure enantiomer, wherein Ar has meaning as defined above and R6 is on O-protecting group with a lower alkyl ester of formic acid; (b) then condensing the compound so obtained with a compound of the formula wherein R8 is hydrogen or COOR3and R3 is lower alkyl; (c) then cyclizing the compound so obtained to a compound of the formula as a substantially pure enantiomer; (d) and then condensing the compound so obtained (1) with a carbocyclic aroyl isothiocyanate and treatment of the product so obtained with an alkyl halide followed by anhydrous ammonia; or (2) with cyanamide in acid, optionally followed by treatment with a base.