Triethylamine → 2-(2-Methanesulfonyloxyethyl)-1-methyl-4-nitrobenzene

A 500 mL round bottom flask was charged with (2-methyl-5-nitrophenyl)acetic acid (15 g, 77 mmol) and dry THF (300 mL). The mixture was cooled on ice-water and treated dropwise with borane-tetrahydrofurane complex (90 mL, 1M in THF, 90 mmol) during one hour. The reaction mixture was stirred for two hours at room temperature and then poured on ice. The aqueous phase was extracted with ethyl acetate (3×600 mL). The combined organic phases were washed with brine (2×1L) and water (2×1L), dried (Na2SO4) and concentrated in vacuo. The residue was redissolved in dichloromethane (200 mL) and triethylamine (10.8 mL, 78 mmol). The mixture was cooled on ice-water and a mixture of methanesulfonyl chloride (6.05 mL, 78 mmol) dissolved in dichloromethane (100 mL) was added dropwise during 20 minutes. The reaction mixture was stirred for 2 hours at room temperature. The reaction mixture was concentrated in vacuo. The residue was purified by flash chromatography on silicagel (eluent:ethyl acetate/heptane 2:3) to give the title compound (7.8 g). 1H NMR (CDCl3): 2.45 (s, 3H); 2.96 (s, 3H); 3.15 (t, 2H); 4.45 (t, 2H); 7.33 (d, 1H); 7.98-8.11 (m, 2H).

1. temperatureThe mixture was cooled on ice-water
2. additionpoured on ice
3. extractionThe aqueous phase was extracted with ethyl acetate (3×600 mL)
4. washThe combined organic phases were washed with brine (2×1L) and water (2×1L)
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated in vacuo
7. dissolutionThe residue was redissolved in dichloromethane (200 mL)
8. temperatureThe mixture was cooled on ice-water
9. additionwas added dropwise during 20 minutes
10. stirringThe reaction mixture was stirred for 2 hours at room temperature
11. concentrationThe reaction mixture was concentrated in vacuo
12. customThe residue was purified by flash chromatography on silicagel (eluent:ethyl acetate/heptane 2:3)

ORD record

ord-7693847c28514014ab4c4a8e3300fed5

Source dataset

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06743809B2