2-Methoxybenzoic acid → 2-Methoxybenzoyl chloride

Participants

Reaction Steps

O-Anisic acid (0.38 mol) was suspended in 60 mL CHCl3 and 3 drops DMF. A single volume of SOCl2 (4 mole equiv.) was added at room temperature with vigorous reaction and the reaction was then refluxed. The reaction was monitored by IR for disappearance of the carboxylic acid carbonyl stretch at 1740 cm-1 and appearance of the acyl carbonyl stretch at 1780 cm-1. The reaction was judged complete after 24 hours. The solvent and excess reagent were removed via vacuum distillation (86 mmHg) affording the crude o-anisoyl chloride in >95% yield as an oil. The acid chloride was cooled, diluted with 50 mL CHCl3 and added dropwise to a chilled (ice/H2O) solution of TEA and t-butylamine (1.2 mole equiv. each) in 100 mL CHCl3. Once addition was complete, the cooling bath was removed and the mixture stood at ambient temperature. The mixture was washed 3×1.5N HCl, 2×0.5N NaOH, and 1× brine. The chloroform was dried on MgSO4, filtered, and concentrated in vacuo to approximately 93 g oil which was Kugelrohr distilled (110°/0.3 mmHg). The N-t-butyl-o-anisamide was obtained as a yellow oil in 95% yield.

Provenance & Evidence