Process for the preparation of compounds which contain hydantoin groups

Claim 1

A process for the preparation of a hydantoin which comprises reacting at a temperature of 50° to 350°C. a. at least one compound of the formula R.sup.3 (--NCX).sub.z wherein X is O or S; z is an integer of from 2 to 3 and R 3 is an optionally substituted aliphatic radical containing 1-20 carbon atoms, an optionally substituted aromatic radical containing 5-12 carbon atoms, a cycloaliphatic radical containing 5-12 carbon atoms, an aliphatic-aromatic radical containing 6-20 carbon atoms or an aromatic or cycloaliphatic heterocyclic radical containing 5-12 ring atoms which contains or is substituted by hetero atoms such as N, O or S, with b. at least one α-halocarboxylic acid selected from the group consisting of ##EQU11## wherein Hal is halogen; R 4 is an optionally substituted aromatic radical containing 5-10 carbon atoms, an aliphatic radical containing 1-20 carbon atoms, a cycloaliphatic radical containing 5-10 carbon atoms, hydrogen or two radicals R 4 taken together with the carbon atom to which they are attached form a cycloaliphatic ring of 5-7 ring members; R 6 is an aliphatic radical containing 1-10 carbon atoms, a cycloaliphatic radical containing 5-10 carbon atoms, an aliphatic-aromatic radical containing 6-10 carbon atoms or an aromatic radical containing 5-10 carbon atoms and y is an integer of from 1 to 3.