These common heterocyclic compound, 6937-34-4, name is 3-Iodophthalic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. category: iodides-buliding-blocks
[0030] The synthesis of mIBX is readily accomplished from commercially available 3-nitrophtalic acid as follows: esterification of 3-nitrophtalic acid via the corresponding acid chloride to give nitrodiester (100%), which upon catalytic hydrogenation provides the aminodiester (100%). Diazotization is then performed, followed by iodination of the aminodiester to provide dimethyl 3-iodophthalate in about 91 % yield. This is followed by saponification, then acidification of dimethyl 3-iodophthalate to give 3-iodophthalic acid in about 93 % yield. 3-iodophthalic acid is then oxidized to form the water-soluble MIBX. This process is carried out using KBrO3 in 0.73H2SO4 at 55-60 C. as follows: KBrO3 (5 g, 30 mmol) is added in portions to a suspension of 3-iodophthalic acid (5 g, 17.1 mmol) in 70 ML of 0.73 M H2SO4 over a period of 20 minutes; The mixture is then maintained at 55-60 C. for 12 hours and the resulting clear orange solution is evaporated to yield an off-white solid, which is triturated with 30 ML of water at 0 C. for 2 hours and filtered to obtain a white solid.This is further triturated with hexane (100 ML) for 6 hours and filtered to give MIBX (3.9 g, 71%) as a white solid with a melting point of 258-260 C. The approximately 70% yield for the conversion of 3-iodophthalic acid to MIBX is the isolated yield of MIBX, with the actual conversion near quantitative as evident from monitoring the oxidation of 3-iodophthalic acid to MIBX by 1H NMR spectroscopy. Water-soluble MIBX is isolated as an analytically pure white solid.The synthesis of MIBX from 3-nitrophthalic acid is illustrated in . The physical properties of MIBX are as follows: mp 258-260 C.; IR (KBr), 3503 3469, 3050, 1708, 1631, 1588, 1369, 730, 700 cm-1; 1H NMR (D2O), 300 MHz): delta 8.35 (dd, J=7.9, 1.0 Hz, 1H), 8.09 (t, J=7.9 Hz, 1H), 7.94 (dd, J=7.9, 1.0 Hz, 1H); 13C NMR (D2O, 75 MHz): delta 125.5, 127.5, 132.5, 134.7, 137.0, 147.1 (ring carbons), 168.9, 172.9 (carbonyl carbons).
The synthetic route of 3-Iodophthalic acid has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Vinod, Thottumkara K.; Thottumkara, Arun P.; US2004/30187; (2004); A1;,
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com