Benzoic acid, 4-amino-3-hydroxy-, methyl ester → Methyl 2-methylbenzo[d]oxazole-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

In a 50 ml round-bottomed three-necked flask equipped with a 12-inch Vigraux column and a Dean Stark trap assembly were placed methyl 4-amino-3-hydroxybenzoate (10.0 g, 60 mmole), trimethylorthoacetate (10.8 g, 90 mmole), and concentrated sulfuric acid (0.25 g, 2.6 mmole). The resulting well-stirred mixture was heated at 115° C. until approximately 8 ml of methanol were collected in the Dean Stark trap. The reaction mixture was heated at 160° C. for another 60 minutes. The reaction mixture was cooled to room temperature and dissolved in ethyl acetate. The resulting organic solution was extracted sequentially with saturated aqueous sodium bicarbonate (1×100 ml), water (2×50 ml), brine, and dried over anhydrous magnesium sulfate. The solvent was removed in the rotary evaporator yielding 7.1 g of the expected methyl 2-methylbenzoxazole-6 carboxylate used as such in the next step.

Provenance & Evidence