PURPOSE: To obtain the titled compound useful as a raw material of synthetic resin, adhesive and organic synthesis, continuously, by reacting acetaldehyde with methanol until the reaction reaches equilibrium, separating the azeotropic mixture of acetaldehyde dimethyl acetal and methanol from the reaction product, and thermally decomposing the mixture.

CONSTITUTION: The preparation of methyl vinyl ether from acetaldehyde and methanol via acetaldehyde dimethyl acetal is carried out as follows: Acetaldehyde is made to react with 1W3 times moles of methanol in the reactor A in the presence of an acid catalyst at 0W60°C until the reaction reaches the equilibrium state. The reaction liquid 3 is distilled in the first distrillation column B, and the liquid extracted from the top of the column is distilled in the second distillation column C. A mixture of acetaldehyde dimethyl acetal and methanol is extracted from the bottom of the column C, and fed to the third distillation column D. The above azeotropic mixture is discharged from the top of the column D, and thermally decomposed in the second reactor E, to obtain the objective compound from the top of the reactor.

EFFECT: The objective product, the intermediates, and the unreacted raw materials can be effectively separated, recovered and reused.