3-methoxy-4-methyl-5-nitrobenzoic acid synthesis

Yield:1002110-78-2 86%

Reaction Conditions:

Stage #1: 3-methoxy-4-methyl-5-nitrobenzoic acid methyl esterwith water;lithium hydroxide in methanol at 20; for 16 h;
Stage #2: with hydrogenchloride in methanol;water;

Steps:

15A

1.63 g (7.25 mmol) of methyl-3-methoxy-4-methyl-5-nitrobenzoate (Example 14A) is dissolved in a mixture of 30 ml methanol and 10 ml water and 708.8 mg (29 mmol) lithium hydroxide is added. It is stirred for 16 h at RT, then acidified with 2N hydrochloric acid and extracted three times with ethyl acetate. The combined organic phases are dried over sodium sulphate and then the solvent is removed. We obtain 1.49 g of product (86% of th.) as a solid. LCMS (method 2): R_t=2.00 min (m/z=210 (M-H)⁺) ¹H-NMR (400 MHz, DMSO-d₆): δ=13.56 (s, 1H, broad), 7.95 (s, 1H), 7.72 (s, 1H), 3.96 (s, 3H), 2.02 (s, 3H).

References:

US2010/105663,2010,A1 Location in patent:Page/Page column 20