Abstract: Proposed is a novel and very efficient method for the preparation of an N-vinyl compound such as N-vinyl-2-pyrrolidone and N-vinyl-N-ethyl acetamide by the thermal decomposition of an N-(.alpha.-acyloxyethyl) compound which is a novel compound obtained by the addition reaction between an NH group-containing compound such as 2-pyrrolidone and N-ethyl acetamide and a vinyl carboxylate, e.g., vinyl acetate, in the presence of an alkali, e.g. alkali metal hydroxide. The reaction mixture after completion of this addition reaction as such, i.e. without isolating the N-(.alpha.-acyloxyethyl) compound, such as N-(.alpha.-acetoxyethyl)-2-pyrrolidone and N-(.alpha.-acetoxyethyl)-N-ethyl acetamide, is heated to effect in situ formation of the desired N-vinyl compound which can then be isolated by distillation under reduced pressure in a very high overall yield.

Abstract: Proposed are an N-(.alpha.-acyloxyethyl) compound, e.g., (N-(.alpha.-acetoxyethyl)-2-pyrrolidone, which is a novel compound and can be converted into an industrially very important N-vinyl compound, e.g., N-vinyl-2-pyrrolidone, by a thermal decomposition reaction under relatively mild conditions as well as a method for the preparation of such an N-(.alpha.-acyloxyethyl) compound. The N-(.alpha.-acyloxyethyl) compound can be synthesized in a high yield by the addition reaction of an NH group-containing compound, e.g., 2-pyrrolidone, with a vinyl carboxylate, e.g., vinyl acetate, in the presence of an alkaline compound such as alkali metal hydroxides.

Abstract: The invention provides a means for greatly saving the thermal energy consumption in the dehydrating distillation of an aqueous solution of a carboxylic acid such as acetic acid by use of an azeotropically distilling entrainer boiling at a lower temperature than the carboxylic acid and immiscible with water. The improvement proposed by the invention comprises taking at least a part of the entrainer phase separated from the condensate coming from the column top or at least a part of the side-cut fluid abstracted from the refluxing fluid inside the column, evaporating the thus taken fluid into vapor and introducing the vapor into the distillation column at a stage for the introduction of the starting feed or below.

Abstract: A novel and effective catalyst system is provided for application in the preparation of alkenyl esters of carboxylic acids by transesterification reaction. The catalyst system consists of a palladium compound as the main ingredient and a cocatalyst formed of an alkali metal compound and a copper compound, at least one of which is a halide. The catalyst ingredients are adsorbed on a solid catalyst carrier, so that repeated use of the combined catalyst or a continuous operation of the reaction can easily be facilitated.