Spiro heterocyclic compounds. VI. Synthesis of spiro(imidazolidine-4,1'-isoindoline) and related compounds.
作者:SACHIYO TAHARA、MARI SHIGETSUNA、HIROTAKA OTOMASU
DOI:10.1248/cpb.30.3133
日期:——
Nitrosation of 2-methylisoquinoline-1, 3 (2H, 4H)-dione (I) with NaNO2 in AcOH afforded the 4-nitroso compound (II) in almost quantitative yield. Catalytic reduction of II produced 4-imino-2-methylisoquinoline-1, 3 (2H, 4H)-dione (III) and a small amount of 4, 4'-bi-2-methylisoquinoline-1, 3 (2H, 4H)-dione (IV). Acidic hydrolysis of III gave 2-methylisoquinoline-1, 3, 4 (2H)-trione (V). The hydrogenated mixture of II was allowed to react with methyl- and phenylisocyanate under an inert atmosphere to give 4-ureido compounds (VIIa, b) in yields of 79% (both). Dehydrogenation of VIIa, b with Pd-C afforded the 4-carbamoylimino compounds (VIIIa, b) in 60 and 87% yields, respectively. When their methanol solutions were refluxed with base catalyst, the compounds (VIIIa, b) were transformed into spiro [imidazolidin-4, 1'-isoindoline]-2, 3', 5-triones (XIIa, b) in yields of 80 and 86%, respectively.
用 NaNO2 在 AcOH 中对 2-甲基异喹啉-1,3 (2H, 4H)-二酮 (I) 进行亚硝基化反应,几乎可以得到 4-亚硝基化合物 (II)。催化还原 II 生成 4-亚氨基-2-甲基异喹啉-1,3 (2H, 4H)-二酮 (III) 和少量 4,4'-bi-2-甲基异喹啉-1,3 (2H, 4H)-二酮 (IV)。III 酸性水解后得到 2-甲基异喹啉-1,3,4(2H)-三酮(V)。将 II 的氢化混合物在惰性气氛下与甲基和苯基异氰酸酯反应,得到 4-脲基化合物(VIIa、b),收率均为 79%。用 Pd-C 对 VIIa、b 进行脱氢反应,可得到 4-氨基甲酰亚胺化合物(VIIIa、b),收率分别为 60%和 87%。当它们的甲醇溶液在碱催化剂的作用下回流时,化合物(VIIIa、b)转化为螺[咪唑啉-4,1'-异吲哚啉]-2,3',5-三酮(XIIa、b),收率分别为 80%和 86%。