Description
Methyl 2-methyl-3-nitrobenzoate is an important organic synthetic material and pharmaceutical intermediate compound. It can be used for the preparation of the anticancer drug lenalidomide as well as other organic compounds (e.g., indole-4-carboxylic acid methyl ester, 5-nitroisocoumarin, 5-aminoisoquinolin-1(2H)-one, etc.).
Uses
Methyl 2-methyl-3-nitrobenzoate may be used in the synthesis of methyl indole-4-carboxylate, 5-aminoisoquinolin-1(2H)-one, 5-nitroisocoumarin and [2-(4-fluorophenyl)-1H-indol-4-yl]-1-pyrrolidinylmethanone. It may also be used in the preparation of substituted nitrostyrene benzoic acids, via reaction with aromatic aldehydes in the presence of DBU in DMSO; and 4-(hydroxymethyl)-1-tosylindole, via Batcho-Leimgruber modification of the Reissert indole synthesis.
Synthesis
2-Methyl-3-nitrobenzoic acid (40.0 g, 0.22 mol) was suspended in methanol (500 mL) and thionyl chloride (32.6 mL, 0.44 mol) was added slowly. The reaction mixture was heated to reflux and kept for 2 hours. Upon completion of the reaction, the mixture was poured into water (500 mL) and stirred to precipitate a white solid. The solid product was collected by filtration, the filter cake was washed with water and subsequently dried under reduced pressure to afford methyl 2-methyl-3-nitrobenzoate (42 g) in 98% yield.
References
[1] Patent: CN105523939, 2016, A. Location in patent: Paragraph 0064; 0065; 0066; 0067
[2] Bioorganic and Medicinal Chemistry Letters, 2015, vol. 25, # 20, p. 4557 - 4561
[3] Patent: CN108218833, 2018, A. Location in patent: Paragraph 0037; 0038; 0049; 0051; 0052; 0065; 0066
[4] Tetrahedron Letters, 2007, vol. 48, # 31, p. 5465 - 5469
[5] Tetrahedron, 2018, vol. 74, # 12, p. 1207 - 1219
