Phosphoric Acid → HCID 22868491, compound

Participants

Reaction Steps

Acetic anhydride (660 ml; 6.975 mol) was added to the solution of the trans-(+/-)-2-(2,4,6-trimethoxyphenyl)cyclohexanol (II; 60 g; 0.225 mol) in dichloromethane (300 ml) at room temperature, while stirring. It was followed by the dropwise addition of orthophosphoric acid (85%; 40 ml; 0.347 mol) over 45 min. Reaction progress was monitored by TLC (tlc system 30% ethyl acetate-pet ether; spray reagent--anisaldehyde; product Rf--value=0.5). TLC of the reaction mixture after 15 min. revealed complete consumption of the starting material. The reaction mixture was then diluted with 250 ml of cold water, neutralized with solid sodium bicarbonate and extracted with dichloromethane (3×500 ml). The combined organic layer was washed with bicarbonate solution, water, brine and dried over sodium sulphate. It was then concentrated in-vacuo and the residue chromatographed over silica gel (column diam. 9.0 cm; silica gel--1 kg; eluent--5% and 10% ethyl acetate-pet ether) to get the title compound (64 gm; yield 81%; m.p. 82-85° C.).

Provenance & Evidence