公开(公告)号：US4366321A

公开(公告)日：1982-12-28

申请号：US257450

申请日：1981-04-24

申请人： Leslie Shuttleworth ,  David Mullen

发明人： Leslie Shuttleworth ,  David Mullen

IPC分类号： C07D333/28 ,  C07D333/42 ,  C07D333/00 ,  C07D333/24

CPC分类号： C07D333/42 ,  C07D333/28

摘要： Disclosed are novel intermediates and their preparation, and the preparation therefrom of 2-halo-3-nitro-5-acyl thiophenes which themselves are important intermediates for the preparation of azo dyes of the type, ##STR1## wherein C.sup.1 represents typically any aniline, tetrahydroquinoline, benzomorpholine or the like coupler and the acyl group contains from 1-10 carbons. It has been found that if 2-acyl thiophene is treated with a hydroxylamine compound, e.g., a salt of hydroxylamine, including sulphate, chloride or the like, to form the oxime prior to the 2-position halogenation and 3-position nitration steps, various side reactions such as halogenation of the acyl group and nitration of the 5-position are avoided, the yield of each step is improved, and the reactions are less sensitive to the deleterious effects of temperature variations and excess reactants. The oxime derivative is readily reconverted to the acyl derivative after the halogenation and nitration steps have been completed. This product is then readily aminated to give the 2-amino derivative.

摘要翻译： 公开了新的中间体及其制备方法及其制备2-卤-3-硝基-5-酰基噻吩，其本身是制备类型的偶氮染料的重要中间体，其中C1代表任何苯胺， 四氢喹啉，苯并吗啉等，酰基含有1-10个碳原子。 已经发现，如果在2-位卤化和3-位硝化步骤之前用羟胺化合物（例如羟胺，包括硫酸盐，氯化物等）处理2-酰基噻吩以形成肟， 避免了各种副反应如酰基的卤化和5-位的硝化，每个步骤的产率提高，并且反应对温度变化和过量反应物的有害影响较不敏感。 在卤化和硝化步骤完成后，肟衍生物容易再转化为酰基衍生物。 然后将该产物很容易地胺化得到2-氨基衍生物。