申请人:Imperial Chemical Industries Limited
公开号:US04348322A1
公开(公告)日:1982-09-07
The invention is concerned with novel dioxolane derivatives of the formula: ##STR1## in which R.sub.a is hydrogen or (1-4C)alkyl and R.sub.b is (1-4C)alkyl or phenyl optionally bearing a halogeno substituent; their production; and their use for the manufacture of certain known anti-arthritic acids of the formula: ##STR2## and, in particular, those acids in which R.sub.a =R.sub.b =methyl or R.sub.a =ethyl and R.sub.b =phenyl, by a novel reduction process. The preferred reduction procedures involve the use of an alkali metal borohydride or cyanoborohydride in the presence of a noble metal catalyst, or the use of an .alpha.-branched alkyl or cycloalkyl Grignard agent. The use of the derivatives of formula I avoids the need for potentially toxic reagents and reactive intermediates in the previously known processes for the production of the acids of formula V.
本发明涉及一种新的二氧六环衍生物,其化学式为:## STR1 ## 其中,Ra为氢或(1-4C)烷基,Rb为(1-4C)烷基或苯基,可选地带有卤素取代基;它们的制备方法;以及它们用于制造某些已知的抗关节炎酸的化学式:## STR2 ## 特别是那些R.sub.a = R.sub.b = 甲基或R.sub.a = 乙基且R.sub.b =苯基的酸,通过一种新的还原过程。首选的还原程序涉及在贵金属催化剂存在下使用碱金属硼氢化物或氰硼氢化物,或使用α-支链烷基或环烷基格氏试剂。使用化合物I的衍生物避免了以前已知的制备化合物V的过程中需要使用潜在有毒试剂和反应中间体的需要。