Regioselective Synthesis of Polyheterocycles From 4-Cyclohex-2-ENYL-3-Hydroxy-1-Methylquinolin-2(1H)-One
作者:K. C. Majumdar、A. K. Kundu
DOI:10.1080/00397919608003824
日期:1996.11
4-Cyclohex-2-enyl-3-hydrocy-1-methylquinolin-2(1H)-one (4) was prepared in 90% yield by the thermal [3,3]sigmatropic rearrangement of 3-cyclohex-2-enyloxy-1-methylquinolin-2(1H)-one (3) in refluxing chlorobenzene for 10 h. compound (4) was cyclised through a sequence of reactions viz. i) acetylation ii) addition of bromine and iii) treatment of the acetyl dibromo compound (6) with base to give a bicyclic product (7) in 90% yield. Treatment of compound 4 with pyridine hydrobromide perbromide in dichloromethane at 0-5 degrees C afforded a cyclic product 8 in excellent yield. Compound 4 when treated with cold cone. sulphuric acid at 0-5 degrees C furnished the bicyclic product 12 in 89% yield.