4-Nitrophenol → HCID 18316643, compound

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Reaction Steps

A mixture of 4-methoxybenzoxazole-7-carboxylic acid (0.16 g), dimethylaminopyridine (catalytic) 4-nitrophenol (0.17 g) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.17 g) in dichloromethane (30 ml) was stirred at room temperature under nitrogen overnight. The mixture was diluted with dichloromethane (20 ml) and washed with water (2×50 ml). The combined organic phases were dried over magnesium sulphate and evaporated in vacuo to give 4-nitrophenyl 4-methoxybenzoxazole-7-carboxylate. 4-Amino-3,5-dichloropyridine (0.15 g) was dissolved in N,N-dimethylformamide (5 ml) at room temperature under nitrogen. Sodium hydride (40 mg; 60% disopersion in oil) was added, and the mixture stirred for 1 h before addition of the 4-nitrophenyl ester (0.26 g) in N,N-dimethylformamide (20 ml). After stirring for 60 h, the N,N-dimethylformamide was evaporated in vacuo, and the residue partitioned between ethyl acetate (40 ml) and water (40 ml). The combined organic phases were washed with water (2×40 ml), dried over magnesium sulphate, evaporated onto silica and purified by flash chromatography eluting with 50% ethyl acetate in hexane) to yield the title compound as a white solid (51 mg).

Provenance & Evidence