Process for the preparation of bisoxazolidines containing urethane groups

Claim 1

Process for the preparation of bis-oxazolidines of general formula (I): wherein R represents a bivalent group selected from linear or branched alkylene, alkylene-cycloalkylene, arylene-alkylene, cycloalkylene and arylene, said groups, with the exception of alkylene, being optionally substituted by up to 4 lower alkyl groups; R₁ and R₂, the same or different, represent hydrogen, linear or branched C₁-C₆ alkyl, cycloalkyl or aryl or, taken together with the carbon atom to which they are linked, R₁ and R₂ represent a saturated C₅-C₇ cycloalkyl group; said process comprising the reaction of an N-hydroxyethyl oxazolidine of general formula (II) with a dicarbamate of general formula (III): wherein R, R₁ and R₂ have the above mentioned meanings and R₅ represents an optionally unsaturated linear or branched C₁-C₁₀ alkyl group or a cycloalkyl group optionally substituted with one or more alkyl groups and/or an aryl group; in the presence of a transesterification catalyst and under conditions of temperature and pressure such as to allow the removal of the also formed alcohol of general formula R₅OH from the reaction medium by distillation.