Yield:886501-03-7 46%

Reaction Conditions:

Stage #1: 2-chloro-6-fluoro-3-methylbenzoic acidwith diphenyl phosphoryl azide;triethylamine in tetrahydrofuran at 25; for 4 h;Reflux;
Stage #2: with water in tetrahydrofuran; for 1 h;Reflux;

Steps:

5 2,3-Difluoro-4-methylaniline

2,3-Difluoro-4-methylaniline
To a mixture of 2-chloro-6-fluoro-3-methylbenzoic acid (1 equiv.) in THF (0.45 M) was added DPPA (1.07 equiv.) and TEA (3 equiv.) at 25° C.
The mixture was stirred at 25° C. for 2 h, then the mixture was heated to reflux for 2 h.
Water was added to the reaction and the mixture was refluxed for 1 h.
The mixture was concentrated to a residue, which was purified by silica gel chromatography to give 2-chloro-6-fluoro-3-methylaniline (46%) as a yellow oil. ¹H NMR (400 MHz, CDCl₃) δ ppm: 6.83 (dd, J=8.4, 10.3 Hz, 1H), 6.56 (dd, J=5.8, 8.3 Hz, 1H), 4.08 (br.s., 1H), 2.31 (s, 1H).

References:

US2016/96841,2016,A1 Location in patent:Paragraph 0253