5-Aminoisophthalic acid monomethyl ester

1955-46-0

28179-47-7

Example 14: Synthesis of methyl 5-((1R,2S)-2-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidine-1-carbonyl)cyclohexylcarbamoyl)biphenyl-3-carboxylate Step 1: Preparation of 3-amino-5-(methoxycarbonyl)benzoic acid Under argon protection, 20% Pd(OH)2 (0.50 g) was carefully wetted with methanol (5 mL), followed by addition of a methanol (20 mL) solution of 3-(methoxycarbonyl)-5-nitrobenzoic acid (5.00 g, 22.2 mmol). The mixture was placed in a Parr shaker and hydrogenated under 50 psi hydrogen pressure for 5 hours. Upon completion of the reaction, the reaction mixture was carefully filtered through glass fiber filter paper under argon protection. The filtrate was concentrated to give the off-white solid product 3-amino-5-(methoxycarbonyl)benzoic acid (4.0 g, 20.5 mmol, 92% yield). Mass spectrometry analysis resulted in (M-H)+ = 194.