An unusual reaction where an allylic methylene is converted into an ethyl ester by means of Wohl-Ziegler's reagents is presented : The reaction of 4-acetyl-1-methyl-2-phenyl-1, 2, 3, 10-tetrahydro-4H-pyrazolo [3, 4-c] [1, 5] benzothiazepin-3-one (7) with N-bromosuccinimide or N-bromoacetamide in commercial (ethanol-containing) chloroform gave ethyl 3-acetyl-5'-oxo-1'-phenyl-spiro [benzothiazoline-2, 4'-[2] pyrazoline]-3'-carboxylate (8). Similarly ethyl 3, 5'-dioxo-1'-phenyl-spiro [benzo [b] thiophene-2 (3H), 4'-[2] pyrazoline]-3'-carboxylate (11) was obtained from 1-methyl-2-phenyl-1, 2, 3, 10-tetrahydro-4H-pyrazolo [3, 4-c] [1] benzothiepin-3, 4-dione (10).
提出了一种不寻常的反应,其中烯丙基亚甲基通过 Wohl-Ziegler 试剂转化为
乙酯: 4-乙酰基-1-甲基-2-苯基-1, 2, 3, 10-四氢-4H- 的反应
吡唑并[3, 4-c] [1, 5]苯并
硫氮杂卓-3-酮(7)与N-
溴代琥珀
酰亚胺或N-
溴乙酰胺在商业(含
乙醇)
氯仿中反应得到乙基3-乙酰基-5'-氧代-1' -苯基-螺[
苯并噻唑啉-2, 4'-[2]
吡唑啉]-3'-
羧酸酯(8)。类似地,从 1-甲基- 得到 3, 5'-二氧代-1'-苯基-螺[苯并[b]
噻吩-2 (3H), 4'-[2]
吡唑啉]-3'-
甲酸乙酯 (11) 2-苯基-1, 2, 3, 10-四氢-4H-
吡唑并[3, 4-c] [1]苯并
硫杂平-3, 4-二酮(10)。