Ethanol → 2-p-tolylbenzo[d]oxazole-5-carboxylic acid

Reaction equation

[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[O:9][C:10]3[CH:16]=[CH:15][C:14]([C:17]([O:19]C)=[O:18])=[CH:13][C:11]=3[N:12]=2)=[CH:4][CH:3]=1.[OH-].[Na+].C(O)C>O>[CH3:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[O:9][C:10]3[CH:16]=[CH:15][C:14]([C:17]([OH:19])=[O:18])=[CH:13][C:11]=3[N:12]=2)=[CH:6][CH:7]=1

Participants

Procedure

A solution containing 16.0 g. (0.06 mole) of methyl 2-(4-methylphenyl)-5-benzoxazolecarboxylate (1a), 4.0 g. (0.1 mole) of sodium hydroxide, and 50 ml. of water in 275 ml. of ethanol was stirred at 25° for 16 hours. The reaction mixture was poured into 1 l. of water. Acidification gave a white precipitate which was filtered, washed with water, and when air-dried amounted to 14.44 g. (95%) of 2-(4-methylphenyl)-5-benzoxazolecarboxylic acid (1b). The ir and nmr spectra were consistent with the proposed structure.