Dimethylformamide → N-(4-chloro-3-methylisothiazol-5-yl)-alpha-[(dimethylamino)methylene]-[2-(2,2-dimethylpropyl)benzoxazol-5-yl]acetamide

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Reaction Conditions

Reaction Steps

N-(4-Choro-3-methylisothiazol-5-yl)-[2-(2,2-dimethylpropyl)benzoxazol-5-yl]acetamide (2.5 g, 0.0066 mole) [prepared as in Example 1] and N,N-dimethylformamide dimethylacetal (1.5 g, 0.013 mole) were added to a mixture of N,N-dimethylformamide (5 ml) and toluene (20 ml) and the resulting mixture was heated to 110° C. for 4 hours. The mixture as cooled to room temperature and the solvent was evaporated in vacuo. The residue was taken up in ethyl acetate and washed sequentially with brine and water, dried over anhydrous magnesium sulfate, filtered and the filtrate evaporated in vacuo. The residue was further purified by flash column chromatography, eluting with ethyl acetate:hexane at 1:1 by volume. Further flash column chromatography, eluting with ethyl acetate:dichloromethane at 1:9 by volume gave N-(4-chloro-3-methylisothiazol-5-yl)-α-[(dimethylamino)methylene]-[2-(2,2-dimethylpropyl)benzoxazol-5-yl]acetamide (0.78 g) as a single geometrical isomer.

Provenance & Evidence