Hydrochloric Acid → HCID 21488671, compound

Participants

Reaction Steps

To a solution of 114 g. (1.0 mole) of m-difluorobenzene in 800 ml. of dry tetrahydrofuran cooled to -50° C. and maintained under a nitrogen atmosphere was added, with stirring, 320 ml. of an n-heptane solution of n-butyl lithium containing 1.0 mole of the latter. The addition was carried out during 50 minutes and was followed by stirring 2 hours more at -50° C. The cold solution was then added with stirring during 50 minutes to a solution of 187.8 g. (0.97 mole) of 6-chloro-2-methyl-4H-3,1-benzoxazin-4-one [J. Am. Chem. Soc. 70, 2423 (1948)] in 1400 ml. of benzene and 1000 ml. of tetrahydrofuran at 25° C. The mixture was stirred under a nitrogen atmosphere for 20 hours, at which time 1000 ml. of 2N hydrochloric acid was added. The aqueous layer was separated and discarded. The organic layer was filtered to remove suspended solid material and the filtrate was washed with cold, dilute aqueous sodium hydroxide solution. Three layers were present, a light colored aqueous phase, a dark brown aqueous phase, and an organic phase. The organic phase, after being dried with anhydrous sodium sulfate, was concentrated to give 101 g. of a semi-solid which was then extracted with 2100 ml. of hot Skellysolve B hexanes. Evaporation of the extract gave 39.9 g. of crude product of melting point 106°-116° C. Recrystallization of this material from Skellysolve B gave purified 2-acetamido-5-chloro-2',6'-difluorobenzophenone of melting point 118°-120° C.

Provenance & Evidence