Halogen effects in Robinson–Gabriel type reaction of cyclopropanecarboxylic acid N′-substituted-hydrazides with PPh3/CX4
摘要:
We found that the reaction of cyclopropanecarboxylic acid N'- substituted -hydrazides with PPh3/CCl4 proceeded smoothly to give the corresponding normal Robinson-Gabriel type product 2-cyclopropyl-5-substituted-[1,3,4]-oxadiazoles in good yields. Using CBr4 or CI4 instead Of CCl4 in the above system, the ring opening of cyclopropane occurred after dehydration to give the corresponding 2-(3 -halopropyl) -5-substituted-[ 1, 3,4]-oxadiazoles (4 or 5) in good yields. (c) 2005 Elsevier Ltd. All rights reserved.
Halogen effects in Robinson–Gabriel type reaction of cyclopropanecarboxylic acid N′-substituted-hydrazides with PPh3/CX4
摘要:
We found that the reaction of cyclopropanecarboxylic acid N'- substituted -hydrazides with PPh3/CCl4 proceeded smoothly to give the corresponding normal Robinson-Gabriel type product 2-cyclopropyl-5-substituted-[1,3,4]-oxadiazoles in good yields. Using CBr4 or CI4 instead Of CCl4 in the above system, the ring opening of cyclopropane occurred after dehydration to give the corresponding 2-(3 -halopropyl) -5-substituted-[ 1, 3,4]-oxadiazoles (4 or 5) in good yields. (c) 2005 Elsevier Ltd. All rights reserved.
Halogen effects in Robinson–Gabriel type reaction of cyclopropanecarboxylic acid N′-substituted-hydrazides with PPh3/CX4
作者:Yong-Hua Yang、Min Shi
DOI:10.1016/j.tetlet.2005.07.048
日期:2005.9
We found that the reaction of cyclopropanecarboxylic acid N'- substituted -hydrazides with PPh3/CCl4 proceeded smoothly to give the corresponding normal Robinson-Gabriel type product 2-cyclopropyl-5-substituted-[1,3,4]-oxadiazoles in good yields. Using CBr4 or CI4 instead Of CCl4 in the above system, the ring opening of cyclopropane occurred after dehydration to give the corresponding 2-(3 -halopropyl) -5-substituted-[ 1, 3,4]-oxadiazoles (4 or 5) in good yields. (c) 2005 Elsevier Ltd. All rights reserved.