Sulfuric Acid → 6-Aminomethyl-3,4-diethoxy-2-fluorobenzonitrile sulfate

Participants

Reaction Conditions

Reaction Steps

A mixture of 4,5-diethoxy-3-fluorophthalonitrile (2.34 g, 10 mol) prepared in Preparation Example 1, sulfuric acid (0.56 mL, 10 mol), 20% palladium hydroxide-carbon (0.59 g, 50% hydrate) (20% palladium-carbon powder, palladium hydroxide type (hydrate), N.E. Chemical Corporation) and 1,2-dimethoxyethane (23 mL) was stirred at −22° C. under hydrogen atmosphere (atmospheric pressure) for 24 hours. After insoluble matter in the reaction mixture was filtered off, the residue was washed with methanol (23 mL) and the combined filtrate was divided into five equal portions. After one of them was concentrated at room temperature under reduced pressure, 1,2-dimethoxyethane (9.2 mL) was added thereto, and the mixture was stirred. Then, triethylamine (0.56 mL, 4 mol) was added dropwise thereto and the mixture was stirred at room temperature for one hour. Precipitated crystals were filtered, washed with a 5% methanol-1,2-dimethoxyethane solution, and dried at room temperature under reduced pressure to give 0.59 g of the ½ triethylamine solvate of the title compound (yield: 76%) as dark white crystals.

Provenance & Evidence