Anthranilic Acid → 2-Propanamidobenzoic acid

Participants

Reaction Steps

To a room temperature solution of 50.22 g anthranilic acid (I) (370 mmol, 1.00 equiv) dissolved in 200 mL dry DMF was added 35.0 mL propionyl chloride (400 mmol, 1.10 equiv) dropwise by addition funnel over 1.5 h. The addition rate was slow enough to maintain internal temperature of the reaction below 38° C. Upon completed addition of the acid chloride, the heterogeneous reaction mixture was stirred for 2.5 h at ambient temperature and then poured into 1600 mL water. The resulting water/DMF mixture, with white precipitate, was stirred vigorously at ambient temperature for one h, after which time the solid was collected by vacuum filtration, rinsing the solid with cold water (2×100 mL). The product was dried in vacuo over phosphorous pentoxide overnight affording 48.04 g of a white solid. m.p. 120.1° C. 1H NMR (CDCl3) δ1.30 (t, 3H, J=7.4 Hz), 2.52 (q, 2H, J=7.4 Hz), 7.12 (t, 1H, J=7.2 Hz), 7.60 (t, 1H, J=7.1 Hz), 8.13 (d, 1H, J=6.3 Hz), 8.76 (d, 1H, J=7.8 Hz) ppm. MS (ESI−) 192.1 [M−H]−.

Provenance & Evidence