3-Hydroxypyrroles and 1H- pyrrol-3(2H)-ones. Part 10. Alkylation of pyrrolones under basic conditions: regiospecific formation of 3-alkoxypyrroles
作者:Gordon A. Hunter、Hamish McNab、Lilian C. Monahan、Alexander J. Blake
DOI:10.1039/p19910003245
日期:——
Alkylation of 1 -substituted 1 H-pyrrol-3(2H)-ones 1 in the presence of base generally gives a mixture of O-alkylated 3, C, O-dialkylated 4 and C, C-dialkylated 5 products. The proportion of C-alkylation is increased by the use of a soft alkylating agent (e.g. iodomethane) and a solvent of low polarity (e.g. THF), whereas O-alkylation is favoured by hard alkylating agents (e.g. methyl toluene-psulphonate)
的1 -取代的烷基化1个ħ吡咯-3-(2 ħ) -酮1在碱的存在下一般得到的混合物ø烷基化3,Ç,Ò二烷基化4和Ç,Ç二烷基化5种产品。的比例Ç烷基化增加通过使用软烷化剂(例如碘甲烷)和低极性(的溶剂例如THF),而ö烷基化是由硬的烷基化剂有利于(例如甲基甲苯磺酸盐)和偶极非质子溶剂(例如二甲基咪唑啉酮)。后一种条件为广泛的1-取代和1,2-二取代的3-烷氧基吡咯3(65-90%的产率)提供了良好的制备途径。据报道1-叔丁基-3-甲氧基-2-苯基吡咯22的X射线晶体结构。