作者:Toshinori Saito、Norio Saheki、Minoru Hatanaka、Toshiyasu Ishimaru
DOI:10.1002/jhet.5570200117
日期:1983.1
1,3,4-Thiadiazol-2-ylacetic acids 4 were prepared by lithiation of 2-methyl-1,3,4-thiadiazoles 1, followed by treatment with carbon dioxide. Diethyl 1,3,4-thiadiazol-2-ylmalonates 6 were prepared by nucleophilic displacement reaction of the corresponding bromides 5 with diethyl malonate. Introduction of the amino group at the a-position of 4 or 6 was carried out via oximation or bromination to give
通过将
2-甲基-1,3,4-噻二唑1
锂化来制备1,3,4-
噻二唑-2-基
乙酸4,然后用
二氧化碳处理。
二乙基-1,3,4-
噻二唑-2- ylmalonates 6分别用对应的
溴化物的亲核置换反应制备5与
丙二酸二乙酯。通过
肟化或
溴化将
氨基引入4或6位,得到
氨基酯9或4。尝试从9或4制备DL-α-
氨基-1,3,4-
噻二唑-2-基
乙酸 不能成功,因为
氨基酸脱羧太快而不能以游离形式分离。