Phthalic Anhydride → HCID 14478552, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 21.25 g (0.064 mol) of (rac.-5-[2,5-bis(acetyloxy)-3,4,6-trimethylphenyl]-3-methyl-1-pentyn-3-ol), 12.12 g (0.12 mol) of triethylamine, 2.44 g (0.02 mol) of 4-dimethylaminopyridine, and 11.84 g (0.08 mol) of phthalic anhydride in 100 mL of dichloromethane was stirred at 25° C. for 3.0 h, then heated under reflux for 10 h. The reaction mixture was cooled to 25° C. and diluted with 200 mL of diethylether. The solution was washed with 3×150 mL of 1.0N HCl. The aqueous phase was further extracted with 2×200 mL of diethylether. The organic phases were combined and extracted with 3×100 mL of 1.0N ammonium hydroxide. The basic aqueous extracts were combined, cooled in an ice-bath, and acidified carefully to pH 5.0 with approximately 60 mL of cold 6.0N HCl. It was then extracted with 4×200 mL of dichloromethane. The combined extracts were dried over MgSO4. Filtration and solvent removal on a rotary evaporator (35° C., 40 mm) gave a light yellow oily residue. This material was transferred to a flask with about 100 mL of diethylether, and the solvent was evaporated as described above to give a foam, which was further dried at 25° C./0.5 mm for 18 h to yield 31 g of rac.-benzenedicarboxylic acid [3-[2,5-bis (acetyloxy)-3,4,6-trimethylphenyl]-1-ethynyl-1-methylpropyl] ester as a pale yellow foam.

Provenance & Evidence