Studies on pyrazolo(3,4-d)pyrimidine derivatives. XVII. Reactions of 5-benzoyl-4,5-dihydro-6-methyl-1-phenyl-1H-pyrazolo(3,4-d)pyrimidine-4-carbonitrile (The 6-methylpyrazolopyrimidine Reissert compound).
作者:Akira MIYASHITA、Susumu SATO、Naokata TAIDO、Ken-ichi TANJI、Etsuo OISHI、Takeo HIGASHINO
DOI:10.1248/cpb.38.230
日期:——
Acid hydrolysis of the 6-methylpyrazolopyrimidine Reissert compound (6) gave the ring-opened product (12) and the oxazole (13). Alkaline hydrolysis of 6 afforded the 6-methylpyrazolopyrimidine (7) and benzoic acid (15). The anion (1) of 6 mainly underwent both aromatization and rearrangement, resulting in the formation of the 6-methylpyrazolopyrimidinecarbonitrile (20) and the 4-benzoyl-6-methylpyrazolopyrimidine (21) together with by-products such as 7, the dimer (22), the benzoate (23a), and O-benzoylbenzoin (24a). The anion I added to the carbonyl carbon of aromatic aldehydes (8a-c), giving the benzoates (23a-c) together with 7, the O-benzoylaroins (24a-c), and the O-benzoylcyanohydrins (27a, c).
酸水解 6-甲基吡唑嘧啶 Reissert 化合物 (6) 得到开环产物 (12) 和噁唑 (13)。碱性水解 6 得到 6-甲基吡唑嘧啶(7)和苯甲酸(15)。6 的阴离子(1)主要发生芳香化和重排反应,生成 6-甲基吡唑嘧啶甲腈(20)和 4-苯甲酰基-6-甲基吡唑嘧啶(21),以及 7、二聚体(22)、苯甲酸酯(23a)和 O-苯甲酰基安息香(24a)等副产物。阴离子 I 加到芳香醛(8a-c)的羰基碳上,得到苯甲酸盐(23a-c)和 7、O-苯甲酰基苯并呋喃(24a-c)以及 O-苯甲酰基环酐(27a, c)。