2-(4-carboxyphenyl)-1,3-dioxoisoindoline-5-carboxylic acid synthesis

Yield:7702-03-6 84%

Reaction Conditions:

with acetic acid at 20 - 180; for 14 h;

Steps:

2.2 Synthesis of 4-carboxyphenyl-1,3-dioxoisoindoline-5-carboxylic acid (H₂In-4-ba)

In a round bottle, 4-aminobenzoic acid (0.69g, 5.0mmol) in glacial acetic acid (10mL) was slowly added into a solution of trimellitic anhydride (0.96g, 5.0mmol) in glacial acetic acid (30mL), and then the solution was heated to 180°C with stirring for 8h (Scheme S1). After cooling to room temperature, the solution was stirred for further 6h and then the reaction solvents were removed under reduced pressure. The crude residue was washed with deionized water (100mL) to give H₂In-4-ba as white powders. Yield 84% (1.32g, 4.2mmol). ¹H NMR (300MHz, DMSO-d₆): δ 8.42 (dd, J=7.5, 1.2Hz, 1H), 8.32 (d, J=0.6Hz, 1H), 8.09 (dd, J=6.8, 2.1Hz, 3H), 7.61 (dd, J=6.9, 1.8Hz, 2H) ppm. MS (EI⁺): m/z 311.1 [M]⁺ (calcd for C₁₆H₉NO₆: m/z 311.25). Anal. calcd for C₁₆H₉NO₆: C, 61.74; H, 2.91; N, 4.50%. Found: C, 61.93; H, 3.03; N, 4.59%. IR (KBr pellet): ν ν 1782, 1734, 1708, 1605, 1510, 1483, 1429, 1375, 1300, 1218, 1090, 927, 771, 724, 547cm^-1.

References:

Chang, Chung-Yu;Tsai, Meng-Jung;Wu, Jing-Yun [Journal of Solid State Chemistry,2021,vol. 298,art. no. 122129]