1987 Volume 35 Issue 1 Pages 398-401
A facile conversion of the methyl group of 5-amino-6-methyl-3-phenyl-4 (3H) -pyrimidinone (1) or 4-aminoantipyrine (5) to an alkyliminomethyl group by isoselenazole ring formation followed by reaction with alkylamines was carried out. 7-Oxo-6-phenyl-6H-isoselenazolo [4, 3-d] pyrimidine (2), which was obtained from 1 and selenium dioxide, was reacted with alkylamines, such as n-propylamine, isopropylamine and 3-methoxypropylamine, to give 6-alkyliminomethyl-5-amino-3-phenyl-4 (3H) -pyrimidinones (3a-d) in 47-58% yields. Treatment of 3a-d with silica gel gave 5-amino-6-formyl-3-phenyl-4 (3H) -pyrimidinone (4) in 91% yield. Similarly the reaction of 5, 6-dihydro-4-methyl-6-oxo-5-phenyl-4H-pyrazolo [4, 3-c] isoselenazole (6) with alkylamines gave 3-alkyliminomethyl-4-amino-1-phenyl-3-pyrazolin-5-ones (7a-f) in 50-97% yields.
