p-Toluenesulfonic acid → 2-Phenyl-1,3-benzoxazole-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of 4-benzamido-3-hydroxybenzoic acid (2.15 g, 8.4 mmol) in xylenes (12 mL) was added p-TsOH (1.6 g, 8.4 mmol, 1.0 eq) at room temperature then the mixture was heated to 160° C. and stirred overnight. The solvent was removed under reduced pressure then the reaction was quenched with saturated aqueous NaHCO3 and biphasic mixture was extracted by CH2Cl2 (4×80 mL). The solvent was concentrated to give the title compound (2.0 g) which was used in the next step without further purification. LC-MS 237.9 [M−H]−, 240.3 [M+H]+, RT 1.12 min.

Provenance & Evidence