A Novel Ring Enlargement of 2H-Azirine-3-methyl(phenyl)amines via Amidinium-Intermediates: A New Synthetic Approach to 2,3-Dihydro-1,3,3-trimethylindol-2-one
作者:Maged K.G Mekhael、Richard J. Smith、Stefan Bienz、Anthony Linden、Heinz Heimgartner
DOI:10.1515/znb-2002-0410
日期:2002.4.1
2,2,N-Trimethyl-N-phenyl-2H-azirin-3-amine (1a) was prepared by successive treatment of 2,N-dimethyl-N-phenylpropanamide (18) with phosgene, triethylamine, and sodium azide. Reaction of 1a in THF solution with boron trifluoride gave 2-amino-1,3,3-trimethyl-3H-indolium tetrafluoroborate (19) in high yield.T he latter reacted with acetic anhydride in pyridine to give a mixture of N-(2,3-dihydro-1,3,
通过用光气、三乙胺和叠氮化钠连续处理 2,N-二甲基-N-苯基丙酰胺 (18) 制备 2,2,N-三甲基-N-苯基-2H-azirin-3-胺 (1a)。1a 在 THF 溶液中与三氟化硼反应,以高产率得到 2-氨基-1,3,3-三甲基-3H-四氟硼酸吲哚 (19)。后者在吡啶中与乙酸酐反应得到 N-( 2,3-二氢-1,3,3-三甲基吲哚-2-yliden)乙酰胺(22)和2,3-二氢-1,3,3-三甲基吲哚-2-酮(21)。用HCl水溶液水解时, 22 转化为 21。19 和 22 的分子结构是通过 X 射线晶体结构测定建立的。