| 摘要 |
<p>1,186,829. Hydantoin and thiohydantoin derivatives. FARBENFABRIKEN BAYER A.G. 29 Feb., 1968 [1 March, 1967], No. 9784/68. Heading C2C. [Also in Division C3] Polycarboxylic acids or esters containing hydantoin or thiohydantoin rings, e.g. the novel compounds of the formula wherein each of R, R<SP>1</SP> and R<SP>2</SP> is a hydrogen atom or an optionally substituted alkyl or cycloalkyl radical, R<SP>3</SP> is an optionally substituted alkyl, cycloalkyl, aryl, aralkyl or heterocyclic radical, R<SP>4</SP> is an aliphatic, aromatic, araliphatic or heterocyclic radical of valency n, X is an oxygen or sulphur atom and n is from 2 to 4, are obtained by reacting compounds containing 2 to 4 amino succinic acid ester radicals with monoisocyanates or isothiocyanates, and, immediately or subsequently cyclizing the products. The esters may be hydrolysed to the corresponding free acids or converted into other functional derivatives, e.g. by amide formation or transesterification. The compounds are useful as intermediates in the production of condensation polymers, e.g. polyesters and polyamides (see Division C3). The aminosuccinic esters used as starting materials may be obtained by reacting the appropriate maleic or fumaric acid esters with primary polyamines.</p> |
