Synthesis
General procedure for the synthesis of methyl 2,5-diaminobenzoate from methyl 2-amino-5-nitrobenzoate: Methyl 2-amino-5-nitrobenzoate (1 g, 5.1 mmol) was dissolved in tetrahydrofuran (50 ml) in a Parr reactor and degassed. 10% palladium carbon catalyst (150 mg) was added and the reaction system was subsequently hydrogen displaced (evacuated and filled with hydrogen). The reaction was carried out at room temperature for 24 hours under 40 psi hydrogen pressure. Complete consumption of feedstock was confirmed by LC-MS monitoring. Upon completion of the reaction, the catalyst was removed by filtration through a diatomaceous earth pad and the filter cake was washed with methanol. The filtrate was concentrated under reduced pressure to give a brown oily product of about 1 g in >95% yield.
References
[1] Patent: WO2015/138919, 2015, A1. Location in patent: Page/Page column 50; 53
[2] Polish Journal of Chemistry, 1984, vol. 58, # 4/5/6, p. 411 - 424
[3] Journal of the American Chemical Society, 1954, vol. 76, p. 1114,1117
