摘要
用丙氨酸、草酸同步脂化制备的Ｎ－乙氧草酰丙氨酸乙酯（１）在三氯氧磷－三乙胺－甲苯系统中失水环合成４－甲基－５－乙氧基－２－ 唑羧酸乙酯（２），后者经碱水解、酸化、脱羧三步一锅合成４－甲基－５－乙氧基 唑（４），４和２－正丙基－４，７－二氢－１，３－二 庚英经Ｄｉｅｌｓ－Ａｌｄｅｒ反应得加成物，经芳构化、水解后制得维生素Ｂ_６，总收率达５６％。本工艺收率高、成本低、适宜于工业化生产。
A novel synthetic technique of vitamin B6 was established.Ethyl N-ethoxalylalaninate (1) prepared from alanine and oxalic acid by azeotropic fractional distillation was cyclized with POCl_3/Et_3N/toluene to afford 4-methyl-5-ethoxy oxazolecarboxylate (2). 2 was subjected to saponification,acidification and decarboxylation in one-pot procedure to produce 4-methyl-5-ethoxyoxazole (4). 4 reacted with 2-n-propyl-4, 7-dihydro-1, 3-dioxepine by Diels-Alder reaction to give adduct, which was converted to vitamin B6 by conventional procedure.The overall yield of vitamin B6 was 56% based on alanine.
出处
《中国医药工业杂志》
CAS
CSCD
北大核心
1994年第9期385-389,共5页
Chinese Journal of Pharmaceuticals
关键词
吡多辛
维生素B6
恶唑羧酸乙酯
恶唑
合成
pyridoxine
vitamin B_6
ethyl 4-methyl-5-ethoxyoxazolecarboxylate
4-methyl-5-ethoxyoxazole
2-n-propyl-4
7-dihydro-1
3-dioxepine
synthesis
