Patent ID: 9573119
Date: 2017-02-21
CPC Classifications: B01J,C07C

Claim:
1. A process for preparing a 2,3-unsaturated carboxylic acid comprising: contacting a formaldehyde source, a carboxylic acid, and a diluent gas with a condensation catalyst under vapor-phase condensation conditions to obtain the 2,3-unsaturated carboxylic acid; wherein the condensation catalyst comprises a mixed oxide of vanadium (V), titanium (Ti), and phosphorus (P); wherein the diluent gas comprises from about 3 mol % to about 5 mol ° le oxygen, based on the total moles of feed; and wherein the process has a selectivity of greater than about 40% and a conversion of greater than about 40%; wherein the formaldehyde source is a methylene dicarboxylate having the general formula (I): and wherein R is selected from the group consisting of a hydrogen, methyl, ethyl, propyl, iso-propyl, and an alkyl group having 1 to 8 carbons.