Methanol → HCID 69338676, compound

Participants

Reaction Steps

4-Methoxy-1,3-benzenedicarboxylic acid 3-monomethyl ester (formula 7) was prepared by adding at 20° C. under stirring 12 ml of concentrated sulphuric acid, d 1.84, to a suspension of 50 g of 4-methoxyisophthalic acid in 400 ml of methanol; stirring was then continued for 1 hour and then the mixture was poured into ice-water (400 ml). The precipitate was collected and stirred with a saturated solution of sodium hydrogen carbonate; the insoluble residue (15 g) was constituted by 4-methoxy-1,3-benzenedicarboxylic acid dimethyl ester. The filtered solution was adjusted to pH 4.8 by adding 6N hydrochloric acid, thus precipitating the desired monoester, which was collected and washed with water, yielding 28.1 g (52.5%) of white solid. By further acidification of the mother liquor unreacted 4-methoxy-1,3-benzenedicarboxylic acid (9 g) was precipitated and collected. In this way a total recovery of 44.2% was obtained by summing together the recovery of the acid and the dimethyl ester, thus allowing a useful yield of 96.7%.

Provenance & Evidence