抄録
When a mixture of 4-aroyl-1-phenyl-1 H-pyrazolo [3, 4-d] pyrimidines (3) and sodium hydroxide in dimethyl sulfoxide (DMSO) was stirred for 1h at room temperature, migration of the aryl group to the 4-position occurred, i. e., the benzilic acid rearrangement, resulting in the formation of 4-aryl-4, 5-dihydro-1-phenyl-1H-pyrazolo [3, 4-d] pyrimidine-4-carboxylic acids (4). Potassium ferricyanide oxidized the carboxylic acids (4) to the corresponding 4-aryl-1-phenyl-1H-pyrazolo [3, 4-d] pyrimidines (5) with elimination of carbon dioxide. Reaction of 5 with sodium hydroxide in DMSO caused ring fission of the pyrazole portion, to give the corresponding 6-anilino-4-aryl-5-pyrimidinecarbonitriles (11).
