Hydrochloric Acid → 6,7-dimethoxy-1,4-dihydro-3H-isochromen-3-one

Participants

Reaction Conditions

Reaction Steps

Heat at 120° C. for 1 hour a mixture of 19.6 g (100 mmol) of 3,4-dimethoxyphenyl acetic acid (VII), 7.4 g (246 mmol) of paraformaldehyde and 20 ml of concentrated HCl in 100 ml of AcOH. Evaporate to dryness. Add 100 ml of H2O, and extract three times with 200 ml of CH2Cl2. Wash the organic phases with 50 ml of 0.5 N NaHCO3 and dry on Na2SO4. Evaporate to dryness. Allow to crystallize for 2 hours in 50 ml of Et2O.

Provenance & Evidence