| 摘要 |
Compositions of matter are provided comprising a stable, non-vaporous monomeric methylene base selected from a 2-methylenethiazoline; a 2-methylenebenzothiazoline; a 2-methylenenaphthothiazoline; a 2-methylenebenzoselenazoline; and a 2-methylenenaphthoselenazoline. The compositions of the invention are prepared by reacting the parent 2-methyl quaternary salt with a non-hydroxylic base which removes a proton of the heterocyclic salt together with a proton acceptor which inhibits build-up of the hydro salt of the non-hydroxylic base, the reaction being conducted under anhydrous conditions in a non-hydroxylic liquid in which the heterocyclic quaternary salt is sufficiently insoluble to inhibit dimer formation. The compositions of the invention are employed in the preparation of methine dyes. |
