Water → HCID 21831312, compound

Participants

Reaction Conditions

Reaction Steps

To 5 ml of dry tetrahydrofuran solution 0 containing 0.16 ml of 2-bromopyridine was added dropwise 1.0 ml of 1.61M n-butyllithium hexane solution under nitrogen atmosphere at -78° C. After 30 minutes, 3.2 ml of solution of 0.5M zinc chloride in dry tetrahydrofuran was added thereto and the mixture was stirred at -78° C. for 15 minutes and under ice-cooling for 15 minutes. Then, the solution of 50 mg of tetrakis(triphenylphosphine)palladium (0) and 300 mg of 4-trifluoromethanesulfonyloxy-2,2-bistrifluoromethyl-6-nitro-2H-1-benzopyran dissolved in 5 ml of dry tetrahydrofuran was added under ice-cooling to the mixture obtained above. The resultant mixture was warmed to room temperature and stirred for additional 15 hours. Water was added to the reaction mixture which was then extracted with ethyl acetate. 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, CH2Cl2 :hexane=1:1) to obtain 200 mg of 2,2-bistrifluoromethyl-6-nitro-4-(2-pyridyl)-2H-1-benzopyran represented by the following formula having a melting point of 105°-107° C.

Provenance & Evidence