Sodium Hydroxide → 5-Chloro-2-methylbenzotrifluoride

Participants

Reaction Conditions

Reaction Steps

A 1000-ml autoclave which is equipped with a mechanical stirrer and made of stainless steel (SUS-316) was charged with 263.6 g (1.0 mol) of the isomeric mixture (the product of the first step) containing 0.72 mol of 2-trifluoromethyl-4-chlorobenzalchloride as a main component, 84 g (2.1 mol) of sodium hydroxide and 420 g of water. Then, 5.3 g (2.0 wt %) of a metal-carried catalyst (5%-Pd/carbon) was added to the autoclave. The atmosphere of the autoclave was replaced by hydrogen, and the autoclave was put into oil bath to increase the temperature to 30° C. At the same time, stir was started while the hydrogen pressure was maintained at 5 kg/cm2. This started absorption of hydrogen. After the lapse of 4 hr, stir was stopped, and the reaction liquid was allowed to cool down. By analysis, conversion of 2-trifluoromethyl-4-chlorobenzalchloride (purity: 72.1%) was 99.9%. Then, the catalyst and the salt were removed by vacuum filtration. The resultant solution was put into a 1000-ml separating funnel, and then the aqueous phase was removed. The organic phase was washed with 500 ml of water and dried with magnesium sulfate. Then, magnesium sulfate was removed by vacuum filtration. As the result, 171.6 g of 2-methyl-5-chlorobenzotrifluoride (purity: 63.8%) was obtained. The yield of this product was 79.0%.

Provenance & Evidence