Hydrochloric Acid → HCID 178480574, compound

Participants

Reaction Conditions

Reaction Steps

A cold (0° C.) solution of tert-butyl 2-(4-fluorobenzyl)-2-[(8-benzyloxy-6-bromo-2-methyl-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazin-7-yl)carbonyl]hydrazine-carboxylate (12.30 g, 20.45 mmol) in dichloromethane (150 mL) was saturated with anhydrous HCl gas. After stirring at 0° C. for half an hour, the mixture was treated with saturated aqueous sodium bicarbonate. The organic layer was separated, and the aqueous phase extracted with dichloromethane. The organic extracts were combined, washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated under vacuum. The residue was dissolved in benzene and concentrated under vacuum. The residual white solid was used without further purification. A solution of the above 8-(benzyloxy)-6-bromo-N-(4-fluorobenzyl)-2-methyl-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-7-carbohydrazide (5.20 g, 10.37 mmol) and dicyclohexylmethylamine (3.03 g, 15.53 mmol) in anhydrous DMF (100 mL) was purged with nitrogen for 10 minutes. Bis-(tri-tert-butylphosphine)palladium (0) (0.74 g, 1.45 mmol) was added and mixture was heated under an atmosphere of carbon monoxide (400 psi) in a stainless vessel in an oil bath at 90° C. overnight. The mixture was filtered through a pad of Celite. The filtrate was concentrated under vacuum to remove˜80 mL of the solvent. The residue was partitioned between dichloromethane (600 mL) and dilute aqueous HCl. The organic extract was washed with brine, dried over sodium sulfate, filtered, and concentrated under vacuum. As the solution was concentrated to about 20 mL, the solution was cooled in an ice-water bath. The solid precipitated was filtered, washed with cold (0° C.) dichloromethane, and dried in vacuum to provide the titled compound.

Provenance & Evidence