Process and intermediates for the preparation of substituted 1-benzothiazolyl-3,4-dimethyl-3-pyrrolin-2,5(1H)-diones
申请人:SCHERING AKTIENGESELLSCHAFT
公开号:EP0444764A1
公开(公告)日:1991-09-04
The invention relates a new process for the preparation of 1-benzothiazolyl-3,4-dimethyl-3-pyrrolin-2,5(1H)-diones of general formula I
in which R is C₁-C₆-alkyl, C₂-C₆-alkenyl or C₃-C₆-alkynyl. which starts from the known halobenzothiazole of general formula II
in which X is chlorine or bromine, via new alkoxy-, alkenyloxy- or alkynyloxybenzothiazoles of general formula IV
via new nitrobenzothiazoles of general formula V
via new aminobenzothiazoles of general formula VI
and via new imides of general formula VIII.
本发明涉及一种新的制备通式为I的1-苯并噻唑基-3,4-二甲基-3-吡咯烷-2,5(1H)-二酮的过程,其中R为C₁-C₆烷基,C₂-C₆烯基或C₃-C₆炔基。该过程从已知的通式II的卤代苯并噻唑开始,其中X为氯或溴,经过新的通式IV的烷氧基,烯丙氧基或炔丙氧基苯并噻唑,经过新的通式V的硝基苯并噻唑,经过新的通式VI的氨基苯并噻唑,以及经过新的通式VIII的酰亚胺。