HCID 22418375, compound → HCID 22418386, compound

Participants

Reaction Steps

To a cold (0° C.) solution of 1.53 g (3.60 mmoles) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-2-amino-3-trifluoromethylthio-4-cyanopyrrole (made according to the process described in EXAMPLE 13, melting point about 182° C.) in 15 ml of pyridine was added, under inert atmosphere, a solution of 1.46 g (3.6 mmoles) of 80% pyridinium bromide perbromide in 15 ml of pyridine. After 30 minutes, the reaction mixture was poured into cold (0° C.) ethyl ether and a precipitate which formed was removed by filtration. The filtrate was washed with aqueous HCl, aqueous NaOH and water. The organic layer was dried over anhydrous magnesium sulfate and evaporated to yield 1.34 g of a brown solid. This was combined with 230 mg of product from an earlier reaction of 300 mg (0.7 mmole) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-2-amino-3-trifluoromethylthio-4-cyanopyrrole and 0.29 g of 80% pyridinium bromide perbromide. The consolidated products were chromatographed on silica gel eluting with 4:1 v/v hexane-ethyl acetate to give 1.31 g (73%) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-2-amino-3-trifluoromethylthio-4-cyano-5-bromopyrrole (EXAMPLE 12) as a white solid. Recrystallization from hexane/ethyl acetate furnished 910 mg of this product as colorless needles, melting point about 160° C.

Provenance & Evidence