Acetic Acid → HCID 54245800, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 2,6-dichloro-4',5'-dimethoxy-2'-methylbenzophenone (Compound 1; 2.5 g, 7.7 mmol), hydrogen bromide/acetic acid (33%, 10 ml) and glacial acetic acid (10 ml) is stirred for 1.5 h at 75° C., poured into water (100 ml) and twice extracted with dichloromethane (50 ml each). The extracts are combined, dried, and concentrated in vacuo. The resulting oil is applied onto the top of a flash chromatography column (silica gel, 30 g). Elution is carried out with toluene and toluene/acetone, 9:1 (500 ml each). The fractions containing the material with an Rf =0.54 (silica gel; toluene/acetone, 9:1) are combined and the solvent is evaporated in vacuo until a final volume of 20 ml is reached. The solution is then extracted three times with aqueous sodium hydroxide (2N; 30 ml each). The aqueous layer is acidified with hydrochloric acid (6M) and the precipitate is collected by vacuum filtration and dried to give Compound 5 as colorless crystals, 1.1 g, (45.9% y) mp 152° C.

Provenance & Evidence