N-substd. oxazolidine-2,4-di:one derivs. prodn. - by one-pot reaction of alkali cyanate with organic halide and alpha-hydroxy carboxylic acid ester

摘要

In a new process for the prodn. of N-substd. oxazolidine-2,4- dione derivs. (I) by reaction of isocyanates O=C=N-(CA2)n-(CO)m-R (III) with alpha-hydroxy carboxylic acid esters (IV), the isocyanate is generated from an alkali cyanate and an organic halide X-(CA2)n-(CO)m-R1 (V) in the presence of the alpha-hydroxy carboxylic acid ester HOCR2R3COOR4 (IV), the molar ratio of (V) to (IV) is 2:1 to 1:10, reaction temp. is 20-200 deg.C, and the reaction is carried out in the presence or absence of a polar aprotic solvent; (where n and m are 0 or 1; each A (same or different) is H, Me or Et; R2 and R3 are H, opt. halogenated and/or unsaturated 1-4C alkyl, or 6-10C acyl, aralkyl or cycloalkyl; R1 is a group Y or Z; Y is opt. unsaturated 1-4C alkyl or 1-4C alkoxy, opt. substd. by halogen, CN, trihalomethyl or alkoxy; Z is aryl, aryloxy, thioaryl, aralkyl, aralkoxy or cycloalkyl opt. ring-substd.by halogen, CN, NO2, trihalomethyl and/or alkoxy; and X is Cl, Br or I). Cpds. (I) in which m is 1, R1 is 1-4C alkyl or alkoxy and R2 and R3 are H, opt. unsaturated and/or halo-substd. 1-4C alkyl or 6-10C aryl, aralkyl or cycloalkyl are new and claimed. (I) are useful as pesticides and pharmaceuticals or intermediates for pesticides and pharmaceuticals, as stabilisers for plastics, and as additives for lubricants. Simple process enabling (I) to be obtained from organic halides in a single process step.