SYNTHESES WITH NITRILES .95. DEAMINATION OF CYTOSINE DERIVATIVES

Treatment of 2-formyl-3-dimethylamino-propenenitrile (1a) and 2-ethoxy carbonyl-3-dimethylamino-propenenitrile (1b), resp., with substituted ureas led to the 2-cyano-3-ureidoacrylates 2, which can be cyclized un der alkaline conditions to give 5-formyl-5-cyano-, and 5-alkoxycarbony l-2-oxopyrimidine derivatives 3, 6, and 7. Reaction of 3 with isopenty lnitrite gave a mixture of the deaminated and oxidized product 4 and t he oxo derivative 5, which was acetalized during the separation step. Similar reaction with the alkoxycarbonyl derivatives 7 led to the form ation of 1-alkyl-5-alkoxycarbonyl-pyrimidine-2,6-diones 8a-d.