Ethanone, 1-(4-Methyl-2-nitrophenyl) synthesis

Yield:155694-84-1 70%

Reaction Conditions:

Stage #1: 4-methyl-2-nitro-1-(prop-1-en-2-yl)benzenewith ozone in methanol;dichloromethane at -78; for 3 h;
Stage #2: with dimethylsulfide in methanol;dichloromethane at 20;

Steps:

22 Preparation of 1-(4-methyl-2-nitrophenyl)ethan-1-one (C84)

Example 22
Preparation of 1-(4-methyl-2-nitrophenyl)ethan-1-one (C84)
To a reaction flask were added 4-methyl-2-nitro-1-(prop-1-en-2-yl)benzene (11.4 g, 64.3 mmol), dichloromethane (292 mL), and methanol (29.2 mL).
The reaction mixture was cooled to -78° C.
Ozone was bubbled into the reaction mixture, and the reaction mixture was stirred at -78° C. for 3 hours.
The reaction mixture was flushed with nitrogen.
Dimethylsulfide (14.0 mL, 189 mmol) was added, and the reaction mixture was allowed to stir and warm to room temperature overnight.
The reaction was concentrated.
Purification by flash column chromatography using ethyl acetate/hexanes as eluent provided the title compound as an oil (8.90 g, 70%): ¹H NMR (300 MHz, CDCl₃) δ 7.85 (dd, J=1.7, 0.8 Hz, 1H), 7.50 (ddd, J=7.8, 1.7, 0.8 Hz, 1H), 7.35 (dd, J=7.7, 0.9 Hz, 1H), 2.53 (s, 3H), 2.48 (s, 3H).

References:

US2017/64962,2017,A1 Location in patent:Paragraph 0627; 0628