Acetic Anhydride → 6-Amino-3-methyl-1-phenylpyrimidine-2,4(1H,3H)-dione

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Reaction Steps

To a solution of 38 g (0.44 mol) of cyanacetic acid, 200 ml of acetic anhydride and 200 ml of acetic acid was added 60 g of 1-methyl-3-phenylurea. The solution was stirred at 90°-100° C. for some hours. After cooling, 65.5 g of 1-cyanoaceto-1-methyl-3-phenylurea (XV) was filtered off (mp 180° C). This was dissolved in 3 1 of boiling ethanol and 10 ml of 10% soda solution was added. After cooling and filtration, the filtrate was evaporated and the crystals were washed with ethanol. Yield 46.7 g (XVI) NMR.

Provenance & Evidence