Method for handling (2-alkyl) (acryloyl) isocyanate, method for stabilizing (2-alkyl) (acryloyl) isocyanate, method for producing (2-alkyl) (acryloyl) isocyanate, heterocyclic compound, and method for producing heterocyclic compound

A method for producing a (2-alkyl)acryloyl isocyanate represented by formula (1), ##STR52## wherein R.sup.1 represents a hydrogen atom or a lower alkyl group, which comprises dissolving a compound of formula (3) ##STR53## wherein, R.sup.5 represents a hydrogen atom or a lower alkyl group, R.sup.6 represents an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, or an alkynyl group, and R.sup.7 and R.sup.8 each represents a hydrogen atom or a group in which a carbon atom located in the .alpha.-position to carbon atoms constituting a heterocyclic ring does not have a hydrogen atom, provided that at least one of R.sup.7 and R.sup.8 is not a hydrogen atom in a polar solvent having a dielectric constant of 5 or more, wherein, upon contact with said solvent, the compound of formula (3) dissociates into the compound of formula (1) and a compound of formula (2), ##STR54## wherein, R.sup.2 represents an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, or an alkynyl group, and R.sup.3 and R.sup.4 each represents a hydrogen atom or a group which does not cause tautomerism with C.dbd.N in the formula (2), provided that at least one of R.sup.3 and R.sup.4 is not a hydrogen atom.