3-Amino-4-fluoro-2-methyl-benzoic acid methyl ester synthesis

Yield:-

Reaction Conditions:

with hydrogen;palladium on activated carbon in methanol; for 4 h;

Steps:

75

A mixture of a crudely purified product (6.00 g, purity 50%) of methyl 4-fluoro-2-methyl-3-nitrobenzoate and wet palladium carbon (10wt%, 300 mg, 2.81 mmol) in methanol (100 mL) was stirred under hydrogen atmosphere for 4 hr. The catalyst was filtered off through celite, the filtrate was concentrated under reduced pressure, and the residue was purified by flash silica gel column chromatography (ethyl acetate/hexane=1/20→1/10) to give the title compound (2.13 g, yield 42%). ¹H-NMR (CDCl₃) δ: 2.40 (3H, s), 3.79 (2H, br s), 3.87 (3H, s), 6.89 (1H, t, J = 9.2 Hz), 7.25 (1H, dd, J = 8.8, 5.6 Hz).

References:

EP2141150,2010,A1 Location in patent:Page/Page column 84