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0 °C

A solution of methyl 4-cyano-2-methylbenzoate (18.1 g, 0.103 mol) in concentrated sulfuric acid (130 mL) was cooled to −10° C. While maintaining this internal temperature, fuming nitric acid (15.6 mL) was slowly added over a period of 30 min. The reaction mixture was stirred an additional 2.5 h at 0° C., at which time it was poured over 1.0 L of ice and then partitioned with ethyl acetate. The organic layer was washed with saturated sodium bicarbonate, brine, dried over anhydrous magnesium sulfate, and then concentrated in vacuo. The residue was triturated with 10% ethyl acetate/hexanes to afford methyl 4-cyano-2-methyl-5-nitrobenzoate (14.8 g, 65%) as a white powder. The title product was isolated as the major isomer in a 9:1 regioisomeric mixture. 1H NMR (400 MHz, CDCl3), Major: 8.85 (s, 1H), 7.81 (s, 1H), 4.00 (s, 3H), 2.77 (s, 3H); Minor: 8.07 (d, 1H), 7.72 (d, 1H), 3.98 (s, 3H), 2.57 (s, 3H). MS (EI) for C10H8N2O4: 238 (M+H2O).

1. additionwas slowly added over a period of 30 min
2. custompartitioned with ethyl acetate
3. washThe organic layer was washed with saturated sodium bicarbonate, brine
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationconcentrated in vacuo
6. customThe residue was triturated with 10% ethyl acetate/hexanes