Vapor phase hydrolysis of organic chlorides into carboxylic acid over solid acid catalysts: Part 1: Catalyst screening test for hydrolysis of vinylidene-type dichloride Original Research Article

For the vapor phase hydrolysis of a vinylidene-type dichloride into its corresponding carboxylic acid, several efficient catalysts were found. They are acidic mixed metal oxides: WO3–TiO2, WO3–ZrO2, and Nb2O5–TiO2. 1,1-Dichloro-3,3-dimethyl-1-butene (DDB) was effectively hydrolyzed over WO3(1)–TiO2(4) catalyst into 2,2-dimethylbutyric acid (DMBS), a key starting compound for a herbicide, as follows: conversion of DDB, 41%; selectivity to DMBS, 96.3%. The catalytic activity was proportional to the amount of Brønsted acidity with acid strength stronger than H0 ≤− 3.0.