Borane → HCID 23320956, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 4-(4-chlorophenylthio)-3,5-dichlorobenzamide (25.7 g, 77.3 mmol) in tetrahydrofuran (155 ml) was added dropwise over 25 minutes to a stirred 1.0M solution of borane in tetrahydrofuran (232 ml) at ambient temperature under nitrogen atmosphere. The mixture was refluxed for 16 hours, cooled to 0° C., and quenched by addition of 2.0N hydrochloric acid. Solvent was evaporated under vacuum and the residue treated with water (400 ml) and diethyl ether. The mixture was basified with 2.5N aqueous sodium hydroxide, the phases were separated, and the aqueous phase extracted twice with diethyl ether. The combined extracts were washed with water (2X) and brine, dried over anhydrous magnesium sulfate, and evaporated under vacuum. The residual oil was dissolved in methanol (500 ml), treated with concentrated hydrochloric acid, and evaporated to dryness at 50° C. under vacuum. The residue was azeotroped twice with methanol, stirred 30 minutes with diethyl ether (300.ml), filtered, washed with diethyl ether (4X), and dried at 40° C. under vacuum to provide 22.3 g (81%) of 4-(4-chlorophenylthio)-3,5-dichlorobenzylamine hydrochloride, m.p. 217°-219° C. The free base was liberated by suspending the salt (4.0 g) in water, basifying with dilute aqueous sodium hydroxide, and extracting with diethyl ether (3X). The combined extracts were washed with water (2X) and brine, dried over anhydrous magnesium sulfate, and evaporated under vacuum to provide 3.59 g (100%) of oily free base.

Provenance & Evidence