Ethyl chloroformate → HCID 178469236, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 1,2,3,4-tetrahydro-2-cyanoimino-6-methyl-4-(3-nitrophenyl)-5-pyrimidinecarboxylic acid, ethyl ester (565 mg, 1.72 mmoles) in dry tetrahydrofuran (70 ml) and pyridine (2.0 ml) was cooled to 0° C. and treated with ethyl chloroformate (0.17 ml, 2.24 mmoles) dropwise under argon. After the addition was completed, the cooling bath was removed and the reaction was allowed to stir at room temperature for 13 hours. Dry dimethylformamide (2.0 ml) was added and the reaction suspension became a homogeneous solution. It was then treated with triethylamine (0.5 ml) followed by ethyl chloroformate (0.1 ml). The reaction was allowed to stir at room temperature for 1 hour and then diluted with ethyl acetate. It was washed with 1N hydrochloric acid, water, sodium bicarbonate solution and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated. The residue was purified by flash chromatography (10% ethyl acetate in dichloromethane) to provide a light yellow foam (585 mg). This material was combined with another batch of the same product and was crystallized from isopropyl ether-dichloromethane to yield the title compound, melting point 173.5°-175° C.

Provenance & Evidence