Trifluoroacetic acid → 2,3-Dimethylbenzohydrazide

Participants

Reaction Steps

N′-(2,3-Dimethyl-benzoyl)-hydrazinecarboxylic acid, tert-butyl ester (70.3 g, 266 moles) was placed in to a 500 mL round bottom flask. With gentle stirring, 200 mL of trifluoroacetic acid (296 g, 2.6 moles) was slowly added, resulting in a vigorous evolution of gas. The reaction mixture was then stirred at room temperature for 2 hours. Water (ca. 100 mL) was then added slowly to the mixture. The mixture was slowly added to 1 L of a cold 2 M K2CO3 solution, contained in a 2 L beaker, while stirring slowly (evolution of gas). About 200 mL of a 10% NaOH solution and 250 mL of CH2Cl2 were added. The reaction mixture was transferred to a large separatory funnel and gently shaken (gas evolution). The aqueous phase was extracted with CHCl3 and the extracts dried and evaporated to yield a white solid, which was dried in a 50° C. vacuum oven to yield 31.72 g (73% yield) of 2,3-dimethyl-benzoic acid hydrazide. 1H NMR (CDCl3, 300 MHz) δ (ppm): 7-7.3 (m, 4H), 4.00 (br s, 2H), 2.271 (s, 6H).

Provenance & Evidence