Lactams. XX. Decarboxylation of unsaturated acids incorporated into six-membered lactam systems.
作者:TOZO FUJII、MASASHI OHBA、HIROSHI KOGEN、YUKO UEDA
DOI:10.1248/cpb.29.3392
日期:——
The thermal decarboxylation of some unsaturated acids (1, 5, 6, 8, and 9) incorporated into six-membered lactams was examined. Although 8 and 9 did not undergo decarboxylation when heated neat at 175-180°C and 240-245°C, respectively, for 2 h, 1, 5, and 6 were decarboxylated in 1, 1, 2, 2-tetrachloroethane at 135°C. The relative ease of the reaction was in the order of 1≥6»5. In the case of 1, the rate-decreasing effects observed on dilution and on the addition of trichloroacetic acid suggest the reaction to be a dimeric intermolecular process.
研究了一些与六元内酰胺结合在一起的不饱和酸(1、5、6、8 和 9)的热脱羧反应。虽然 8 和 9 分别在 175-180°C 和 240-245°C 温度下加热 2 小时后没有发生脱羧反应,但 1、5 和 6 在 135°C 的 1,1,2,2-四氯乙烷中发生了脱羧反应。在 1 的情况下,稀释和加入三氯乙酸时观察到的速率降低效应表明该反应是分子间的二聚过程。