Chlorosuccinimide → N-Hydroxy-4-isobutylbenzenecarboximidoyl chloride

To a solution of 4-isobutylbenzaldehyde oxime (1.0 g, 5.6 mmol) that was obtained in Example 9 (9e) in N,N-dimethylformamide (10 ml) was added N-chlorosuccinimide (0.15 g, 1.1 mmol) with stirring, and furthermore, a small amount of gaseous hydrochloric acid was bubbled into the resulting mixture under stirring, and then the resulting mixture was stirred at room temperature for 10 minutes. After repeating the series of the same procedures described above five times in total, the reaction mixture was poured into ice water (100 ml) and extracted with ether. The extract was washed successively with water and a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. After filtration, the filtrate was evaporated in vacuo to afford the title compound (1.2 g) in a yield of 100% as a yellow oily product.