| 摘要 |
<p>1421310 Citric acid and derivatives SNAMPROGETTI SpA 1 May 1974 [9 May 1973] 19196/74 Heading C2C Citric acid and derivatives thereof are prepared by epoxidizing itaconic acid or derivatives of formula wherein each of R and R<SP>1</SP> which can be the same or different, is a hydrogen atom or a hydrocarbon radical, and either each of X and X<SP>1</SP> which can be the same or different is -CN, -COOR<SP>2</SP>, -COOM, or -CONH 2 where M is a monovalent metal atom or represents part of a metal atom having a valency of at least two and R<SP>2</SP> is a hydrogen atom or a hydrocarbon radical, or X and X<SP>1</SP> together represent a divalent radical and together with the two carbon atoms to which they are attached form a heterocyclic ring with five carbon atoms to give which is reacted with hydrocyanic acid or a cyanide, and the cyanohydrin hydrolysed. An example describes the preparation of the the trimethyl ester of citric acid through sodium salt of epoxyitaconic acid, prepared by the reaction of hydrogen peroxide on itaconic acid in the presence of sodium tungstate.</p> |
