申请人:Reilly Industries, Inc.
公开号:US05493028A1
公开(公告)日:1996-02-20
Disclosed are preferred processes for the preparation of 2-halo-nicotinic acid derivatives of formula (IV): ##STR1## by cyclocondensation of a 4-halo-4-cyanocarbonyl compound of formula (III): ##STR2## wherein X is Cl or Br; Y is a carbonyl group and R.sup.1, R.sup.2 and R.sup.3 are each, independently, H, Cl, Br or an organic radical. Further preferred aspects include the preparation of the above-noted 4-halo-4-cyanocarbonyl compound via Michael addition of a 2-halonitrile with an .alpha.,.beta.-unsaturated aldehyde or ketone, and the preparation of the 2-halonitrile by redistribution of halogen between a 2,2-dihalonitrile and a parent nitrile.
揭示了制备公式(IV)的2-卤代烟酸衍生物的首选方法:##STR1## 通过环缩合制备公式(III)的4-卤代-4-氰基羰基化合物:##STR2## 其中X为Cl或Br;Y为羰基,R.sup.1、R.sup.2和R.sup.3分别独立地为H、Cl、Br或有机基团。进一步的首选方面包括通过2-卤代腈与α,β-不饱和醛或酮的Michael加成制备上述4-卤代-4-氰基羰基化合物,以及通过在2,2-二卤腈和母体腈之间重新分配卤素制备2-卤代腈。