申请人:Biogal Gyogyszergrar
公开号:US05350872A1
公开(公告)日:1994-09-27
The subject matter of the invention is a process for the preparation of carboxylic acids and derivatives of them of the general formula ##STR1## wherein R means hydrogen, or a C.sub.1-4 alkyl or a (C.sub.1-5 alkoxy)carbonyl group, R.sub.1 is as defined in claim 1, R.sub.7 stands for hydrogen or a C.sub.1-7 alkyl group and R.sub.8 means hydrogen or a carboxyl group, by reacting a 1,3-dioxane-4,6-dione derivative of the general formula ##STR2## wherein R.sub.9 stands for a C.sub.1-4 alkyl group or a phenyl group, optionally monosubstituted by halogen and R.sub.10 stands for hydrogen or a C.sub.1-5 alkyl group or R.sub.9 and R.sub.10 together form a pentamethylene group, and an aldehyde or ketone of the general formula ##STR3## in the presence of formic acid.
本发明的主题是一种用于制备通式##STR1##的羧酸及其衍生物的过程,其中R表示氢,或C.sub.1-4烷基或(C.sub.1-5烷氧基)甲酰基,R.sub.1如权利要求1中定义,R.sub.7代表氢或C.sub.1-7烷基团,R.sub.8表示氢或羧酸基团,通过将通式##STR2##的1,3-二氧杂环己烷-4,6-二酮衍生物与通式##STR3##的醛或酮在甲酸存在下反应。其中R.sub.9代表C.sub.1-4烷基或苯基,可选地被卤素单取代,R.sub.10代表氢或C.sub.1-5烷基,或R.sub.9和R.sub.10共同形成一个五亚甲基基团。