反应详情

To a mixture of 200 mg of 2,2-bisfluoromethyl-6-nitro-4-(2-pyridyl)-2H-1-benzopyran and 2 ml of methylene chloride was added dropwise a mixture of 135 mg of (0-mesitylenesulfonyl)hydroxylamine and 3 ml of methylene chloride at room temperature with stirring. The mixture was stirred for 1 hour and ether was added thereto. The separated crystal was collected by filtration to obtain 240 mg of N-amino-2-(2,2-bisfluoromethyl-6-nitro-2H-1-benzopyran-4-yl)pyridinium mesitylenesulfonate. To a mixture of 60 mg of the above-obtained N-amino-2-(2,2-bisfluoromethyl-6-nitro-2H-1-benzopyran-4-yl)pyridinium mesitylenesulfonate and 1 ml of dimethylformamide was added 5 mg of sodium hydride and 36 mg of cyano bromide under ice-cooling with stirring. The mixture was stirred under ice-cooling for 1 hour. Water was added thereto and the mixture was extracted with ether. The organic layer was washed with water and dried. The solvent was distilled off and the resultant residue was purified using silica gel column chromatography (developing solution, MeOH:CH2Cl2 =5:95) to obtain 11 mg of 2-(2,2-bisfluoromethyl-6-nitro-2H-1-benzopyran-4-yl)pyridine N-cyanoimine represented by the following formula having a melting point of 212-214° C.

1. additionwas added dropwise
2. stirringThe mixture was stirred for 1 hour
3. filtrationThe separated crystal was collected by filtration