Process for the production of 2,3,4,5,6,7-hexahydrocyclopenta-(3)-1,3-oxazine-2,4-dione compounds

Process for the production of a 2,3,4,5,6,7-hexahydrocyclopenta-[e]-1,3-oxazine-2,4-dione compound of the formula ##SPC8##

• wherein
• R is alkyl of up to 3 carbon atoms,
• R.sup.1 is alkyl of 1 to 12 carbon atoms, optionally substituted cycloalkyl of 5 to 8 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl with 1 to 6 carbon atoms and 1 or 2 halogen atoms, haloalkyl with 1 to 6 carbon atoms and 1 or 2 halogen atoms, alkoxyalkyl with 1 to 6 carbon atoms in the alkyl moiety and 1 to 4 carbon atoms in the alkoxy moiety, alkylthioalkyl with 1 to 6 carbon atoms in the alkyl moiety and 1 to 4 carbon atoms in the alkylthio moiety, alkoxycarbonylalkyl with 1 to 6 carbon atoms in the alkyl moiety and 1 to 4 carbon atoms in the alkoxy moiety, aralkyl with 6 to 10 carbon atoms in the aryl moiety and 1 to 3 carbon atoms in the alkyl moiety, cycloalkyl-alkyl with 5 to 8 carbon atoms in the cycloalkyl moiety and 1 to 4 carbon atoms in the alkyl moiety, and optionally substituted aryl of 6 to 10 carbon atoms, the optional substituents on the cycloalkyl or aryl radicals being halogen or alkyl with up to 3 carbon atoms;
• and
• n is an integer of from 0 to 6 inclusive,
• which process essentially comprises contacting an adipic acid halide of the formula ##EQU4## wherein R is hydrogen or alkyl of up to 3 carbon atoms;
• and
• X is halogen,
• with about 1 to 1.4 times the molar amount of an isocyanate of the formula
• O=C=N--R.sup.1
• wherein
• R.sup.1 is defined as above,
• in the presence of a tertiary amine, at a temperature from 80.degree. to 180.degree.C.