申请人:SEITETSU KAGAKU CO., LTD.
公开号:EP0245835A2
公开(公告)日:1987-11-19
Novel compounds, 2-(α-alkoxyimino) ethylthiophenes are susceptible to electrophilic substitution reactions, and the acetylation, nitration, sulfonation and halogenation of the compounds provide 5-acetyl-2-(a-alkoxyimino)-ethylthiophenes, 5-nitro-2-(a-alkoxyimino)ethylthiophenes, 5-(a-alkoxyiminolethyl-2-thiophenesulfonic acid and 5-halo-2-(a-alkoxyimino)ethylthiophenes, respectively.
The hydrolysis of 5-acetyl-2-(a-alkoxyimino)-ethylthiophenes readily provides a known compound, 2,5- diacetylthiophene which is an important intermediate for the production of medicines, whereas the haloform reaction provides novel compounds, 5-(a-alkoxyimino)ethyl-2-thiophenecarboxylic acids, the hydrolysis of which compounds readily provides a known compound, 5-acetyl-2-thiophenecarboxylic acids, an important intermediate for the production of medicines.
The hydrolysis of 5-(a-alkoxyimino)ethyl-2-thiophene- sulfonic acids and their salts provide novel 5-acetyl-2-thiophenesulfonic acid and its salts, respectively.
Novel compounds, 2-(a-alkoxyimino)ethylthiophenes are obtained either by 0-alkylation of 2-acetylthiophene oxime or by directly reacting 2-acetylthiophene with an 0-alkylhydroxylamine.
新化合物 2-(α-烷氧基亚氨基)乙基噻吩易发生亲电取代反应,通过乙酰化、硝化、磺化和卤化反应可得到 5-乙酰基-2-(a-烷氧基亚氨基)乙基噻吩、5-硝基-2-(a-烷氧基亚氨基)乙基噻吩、5-(a-烷氧基亚氨基乙基)-2-噻吩磺酸和 5-卤代-2-(a-烷氧基亚氨基)乙基噻吩。
5- 乙酰基-2-(a-烷氧基亚氨基)乙基噻吩的水解反应容易提供一种已知化合物 2,5-二乙酰基噻吩,它是生产药物的一种重要中间体,而卤代反应则提供新化合物 5-(a-烷氧基亚氨基)乙基-2-噻吩羧酸,这种化合物的水解反应容易提供一种已知化合物 5-乙酰基-2-噻吩羧酸,它是生产药物的一种重要中间体。
5-(a-烷氧基亚氨基)乙基-2-噻吩磺酸及其盐类的水解分别提供了新型的 5-乙酰基-2-噻吩磺酸及其盐类。
通过 2-乙酰基噻吩肟的 0-烷基化反应,或通过 2-乙酰基噻吩与 0-烷基羟胺的直接反应,可以得到新型化合物 2-(a-烷氧基亚氨基)乙基噻吩。