4-Hydroxybenzoic Acid → Salicylic Acid

Participants

Reaction Steps

A wholly aromatic copolymer of hydroxybenzoic acid and hydroxynaphthoic acid was prepared by reacting 48.3 g (0.35 mole) of 4-hydroxybenzoic acid with 28.2 g (0.15 mole) of 6-hydroxy 2-naphthoic acid. Dibutyl tin diacetate was used as the catalyst (1800 ppm on total charge). The reaction mixture was heated for 11/2 hrs. at 300° C. and at 320° C. for 30 minutes, by which time it was very viscous. Strong fibers were pulled from the melt. The total yield of water was 17 ml, (94% theory). The isolated polymer had a Tm of 240°, an IV of 6.7 and the FTIR analysis showed a hydroxybenzoic acid/hydroxynaphthoic acid ratio of approximately 65/35.

Provenance & Evidence