Sulfuric Acid → 4-Iodo-2-nitrotoluene

Temperature

2 °C

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).

1. custom2° C.
2. customdid not exceed 0° C
3. additionUpon completion of the addition
4. additionUpon completion of the addition
5. temperaturethe reaction mixture was cooled down to room temperature
6. extractionextracted with methylene chloride (50 mL) four times
7. washThe combined organic phase was washed with saturated NaHCO3 (40 mL) and water (40 mL)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated in vacuo
10. customThe residue was purified by silica gel chromatography

ORD record

ord-1b84c63b2720472c8439f3e183b4de6b

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08148503B2