Hydrochloric Acid → 2-Mercapto-1,3-benzoxazole-5-carboxylic acid methyl ester

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Reaction Steps

In a round bottom flask equipped with a mechanical stirrer, reflux condenser and drying tube were placed 2-amino-4-methoxycarbonylphenol (8,3 g, 0.05 mole), O-ethylxanthic acid potassium salt (8.8 g, 0.055 mole) and pyridine (125 mL). The mixture was stirred and heated at reflux for 2 hours and cooled to room temperature. The mixture was poured into ice and concentrated HCl (50 mL). The product was collected as a solid and washed thoroughly with water. The material was air dried to give 9.9 g (95%) of the 5-methoxycarbonylbenzoxazol-2-thione as a white powder, m.p. 218°-221° C.

Provenance & Evidence