A process for the transesterification of a carboxylic or carbonic acid ester comprises reacting the carboxylic or carbonic acid ester under transesterification conditions with an alcohol in the presence, as catalyst, of either (i) a Group V element-containing Lewis base and an epoxide or (ii) a cyclic amidine. The Lewis base can be an organic compound containing trivalent phosphorus or nitrogen and can be an amine, for example an amidine. The process can be operated in the liquid phase at a temperature of from 15.degree. to 150.degree. C., and the catalyst is employed in solution. Preferred catalysts are those where the cyclic amidine forms part of a fused ring system containing six and five membered rings, six and seven membered rings or two six membered rings.
Improved powder coating compositions comprise a hydroxyl functional binder having carboxylic ester functionality and a transesterification cure catalyst comprising an epoxide and a non-acidic nucleophile, preferably onium salts. Resins such as hydroxyl functional acrylic, hydroxyl functional polyester, ester functional polyesters, and methyl succinate esters of bisphenol epoxides transesterify in the presence of an epoxide and phosphonium salts such as tetrabutylphosphonium acetate and yield coatings having exceptional hardness, impact resistance and solvent resistance at bake temperatures of about 300.degree. F.
Bis(pentaerythritol phosphate) carbonate can be formed by the reaction of pentaerythritol phosphate alcohol and dihydrocarbyl carbonate, such as diphenyl carbonate, preferably in the presence of a transesterification catalyst, such as an imidazole, and in a high boiling organic solvent, e.g., a phosphate ester solvent, which allows for removal of by-product.
A process for producing a dicarboxylic acid monoester which comprises subjecting a dicarboxylic acid monoester or an alkali metal salt of a dicarboxylic acid monoester and a metal alkoxide to transesterification in the presence of an organic solvent, or a process for producing a dicarboxylic acid monoester which comprises subjecting a dicarboxylic acid monoester or an alkali metal salt of a dicarboxylic acid monoester and an alcohol to transesterification in the presence of a metal alkoxide.
A process is disclosed for the cogeneration of ethylene glycol and dimethyl carbonate by reacting methanol and ethylene carbonate in the presence of a heterogeneous, phosphine-bound polymer catalyst. Dimethyl carbonate and ethylene glycol are generated in greater than 98% selectivity.
A process is disclosed for the cosynthesis of ethylene glycol and dimethyl carbonate by reacting methanol and ethylene carbonate in the presence of a homogeneous catalyst from the group consisting of soluble miscible tertiary phosphines arsines, and stibines and soluble, miscible bivalent sulphur and selenium compounds.
