2,6-Difluorobenzoyl chloride

• the preparation of series of novel 2-aryl substituted 4H-3,1-benzoxazin-4-ones
• regioselective synthesis of 3,6-disubstituted-2-aminoimidazo[1,2-a]pyridine
• Friedel-Crafts acylation reaction of toluene, anisol, thioanisol, 4-phenoxyacetophenone and N,N-diacetyl-4-phenoxyaniline

Step 1: In a 250 ml three-necked flask equipped with a reflux condensing device, 2,6-difluorobenzoic acid, anhydrous KF, DMF and a small amount of catalyst were added sequentially, heated to reflux, the reaction was carried out for 8 h. The reaction was cooled, filtered, and the residue of the filtrate was washed with DMF, and the filtrate and the washings were combined, and the DMF was evaporated under reduced pressure, and washed, and filtered to obtain the intermediate product of 2,6-difluorobenzoic acid, a light yellow solid.

Step 2: In a 250 ml dry three-necked flask equipped with a reflux condensing device, add 2,6-difluorobenzoic acid, thionyl chloride and a small amount of catalyst in turn, heating to reflux, the reaction is 4h, evaporate the excess thionyl chloride, to get the product 2,6-difluorobenzoyl chloride, brownish yellow liquid.