Hydrochloric Acid → 2,3-Dichloro-5-(trifluoromethyl)pyridine

Participants

Reaction Steps

A 45 milliliter (ml) Teflon®-lined Parr bomb, which was equipped with a pressure gauge, rupture disk and needle valve, was charged with 2 grams (g) of 3-chloro-2-fluoro-5-trifluoromethylpyridine and then pressurized with anhydrous HCl to 200 psig. The bomb was placed in a heated rocker and kept at 110° C. for 20 hours. The maximum pressure was 220 psig. The bomb was removed from the heater and allowed to cool to room temperature, at which time it was placed in an ice bath. The bomb was vented to a caustic scrubber and 2.5 g of a light tan liquid consisting of HF and 84.3% 2,3-dichloro-5-trifluoromethylpyridine (by wt.). This represents a 97.7% yield of 2,3-dichloro-5-trifluoromethylpyridine (by wt.) with 0.4% of 3-chloro-2-fluoro-5-trifluoromethylpyridine remaining. No additional products were observed by analysis with gas chromatography.

Provenance & Evidence