tert-Butyl 4-aminobenzoate

tert-Butyl 4-aminobenzoate can be used to synthesise structural units for antifolate and a novel liver-targeted coupling of PSN-357, a glycogen phosphorylase inhibitor for the treatment of diabetes. It can also be used in the synthesis of tert-butyl 4-aminobenzoate n-substituted derivatives^[1].

tert-Butyl 4-aminobenzoate is synthesised using tert-butyl 4-nitrobenzoate as raw material by chemical reaction. The specific synthesis steps are as follows:
Tert-butyl 4-nitrobenzoate (4.75 g, 21.279 mmol) was dissolved in MeOH (200 ml) and added with CAUTION was Pd/C (475 mg, 0.1 equiv. w/w) and the flask evacuated prior to purging with N2, re-evacuation and purging with H2. The mixture was stirred under H2 for 5 hours until complete. The mixture was filtered through celite and evaporated to a white solid (4.11 g, 21.269 mmol, quant.). Rf 0.29 [20% EtOAc in Hexane]. Mp. I l l - 113 0C. 1H NMR (400 MHz, CDCl3) δ 7.79 (2H, dt, J=8.6, 2.3 Hz, 2ArH), 6.61 (2H, dt, J=8.6, 2.3 Hz, 2ArH), 4.00 (2H, br s, NH2), 1.56 (9H, s, C(CH3)3) ppm. 13C NMR (100 MHz, CDCl3) δ 165.9 (C=O), 150.4 (ArC), 131.3 (ArCH), 121.7 (ArC), 113.7 (ArCH), 80.0 (C(CH3)3), 28.3 (C(CH3)3) ppm. IR (neat) υmax 3415, 3345, 3235, 2972, 1682, 1598, 1367, 1287, 1154, 1115 cm 1. HRMS mJz calc. C11H15NO2 [M+l] 194.1176, found [M+l] 194.1179.

[1] V. BAVETSIAS  E. H. Synthesis of N-substituted derivatives of tert-butyl 4-aminobenzoate via a palladium-catalysed reaction[J]. Journal of Chemical Research-s, 2000. DOI:10.3184/030823400103168100.