Isopropylamine → 4-Bromo-N-isopropylbenzamide

Participants

Reaction Conditions

Reaction Steps

A solution of 4-bromobenzoic acid (4.00 g, 19.9 mmol, Aldrich: Cat. #108510) and thionyl chloride (10.0 mL, 137 mmol) was heated by microwave irradiation at 100° C. for 1 h, turning the heterogeneous solution to a homogeneous solution. The volatiles were removed in vacuo and the residue was azeotropically washed with dry acetonitrile several times (20 mL×4) to remove excess thionyl chloride. The residue was dissolved in anhydrous methylene chloride (40 mL) and cooled to 0° C. prior to the addition of 2-propanamine (8.0 mL, 94 mmol, 99.5% pure Aldrich [75-31-0]). After 1 hour, the reaction mixture was diluted with methylene chloride (20 mL) and quenched with H2O (5 mL). The layers were separated and the organic layer was washed with H2O (1×5 mL), saturated NaHCO3 (1×5 mL), H2O (1×5 mL), 1 N HCl (3×5 mL), H2O (1×5 mL), and brine (5 mL). The organic layer was dried over Na2SO4, filtered, and concentrated in vacuo to afford the desired product (4.50 g, 93% yield) which was used directly in the next step without further purification. LCMS (M+H)+: m/z=242/244.

Provenance & Evidence