Acetic Acid → HCID 21467105, compound

Participants

Reaction Steps

To a stirred suspension of methyl 4-nitroanthranilate (prepared from 4-nitroanthranilic acid, 14.2 g) in methanol (600 ml) was added propionaldehyde (5.04 g) followed by glacial acetic acid (7.2 ml). Sodium cyanoborohydride (4.56 g) was added and the reaction mixture stirred at room temperature for 16 hours. Further propionaldehyde (5.04 g) and sodium cyanoborohydride (4.56 g) were added and the mixture stirred for a further 24 hours. The solvent was evaporated and the residue partitioned between ethyl acetate and 10% potassium carbonate solution. The organic layer was separated and the aqueous re-extracted with ethyl acetate (2×100 ml). The combined organics were washed with saturated sodium chloride solution then dried (sodium sulphate) and evaporated to give the crude product, which was purified by column chromatography on silica using 10% diethyl ether/petroleum ether (60-80) to afford the required product (3.42 g, 20%). 1H NMR (250 MHz, DMSO-d6) δ0.98 (3H, t), 1.66 (2H, sextet), 3.26 (2H, dq), 3.86 (3H, s), 7.33 (1H, dd), 7.46 (1H, d), 7.88 (1H, t), 8.04 (1H, d).

Provenance & Evidence