Sulfuric Acid → 4-Iodo-2-nitrotoluene

Participants

Reaction Conditions

Reaction Steps

To a suspension of 4-methyl-3-nitroaniline (4.30 g, 28.26 mmol) in water (40 mL) cooled in ice-water bath, 98% sulfuric acid (1.89 mL) was added cautiously (Herm et al., 2002, which is incorporated herein by reference). Sodium chloride was added into the ice-water bath to lower the temperature to minus 2° C., and a solution of NaNO2 (2.15 g, 31.10 mmol) in water (10 mL) was added at a rate that the reaction temperature did not exceed 0° C. Upon completion of the addition, the mixture was stirred at minus 2° C. for 45 minutes. This solution of the diazo compound was then carefully added (in small portions) to a boiling solution of NaI (12.89 g, 86 mmol) (CAUTION: vigorous gas evolution). Upon completion of the addition, the reaction mixture was cooled down to room temperature and extracted with methylene chloride (50 mL) four times. The combined organic phase was washed with saturated NaHCO3 (40 mL) and water (40 mL), dried over Na2SO4, concentrated in vacuo. The residue was purified by silica gel chromatography to yield 4-iodo-2-nitrotoluene (6.07 g, 82%). 1H NMR (400 MHz, CDCl3): δ 8.28 (d, 1H, J=1.8 Hz, Ph-H), 7.81 (dd, 1H, J=2.2 and 8.1 Hz, Ph-H), 7.09 (d, 1H, J=8.1 Hz, Ph-H), 2.55 (s, 3H, CH3).

Provenance & Evidence