Some common heterocyclic compound, 75092-30-7, name is 4-Iodo-1-methyl-1H-pyrazole-5-carboxylic acid, molecular formula is C5H5IN2O2, 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. Formula: C5H5IN2O2
Step 1. 1-Methyl-4-[(4-methylphenyl)amino]-1H-pyrazole-5-carboxylic acid A mixture of 4-iodo-1-methyl-1H-pyrazole-5-carboxylic acid ((Y. A. Manaev et al., J. Gen. Chem. USSR. (Engl. Transl.), 1982, 52, 2291), 2.92 g, 11.6 mmol), p-toluidine (6.20 g, 57.9 mmol), and copper powder (1.17 g, 18.4 mmol) in 5% aqueous sodium carbonate (60 ml) was stirring at 100 C. for 5 h. After cooling to room temperature, diethyl ether (100 ml) and 2N aqueous sodium hydroxide (100 ml) were added. This mixture was filtered through a pad of Celite, which was washed with 2N sodium hydroxide (200 ml) and ether (100 ml). The separated aqueous layer was washed with ether (100 ml), filtered through a pad of Celite again, and acidified with concentrated hydrochloric acid. The precipitate was collected by filtration, and washed with water to give 1.77 g (76.6 mmol, 66%) of the title compound as a gray powder. MS (EI) m/z: 231 (M+). 1H-NMR (DMSO-d6) delta: 7.61 (1 H, s), 7.05 (2 H, d, J=8.6 Hz), 6.98 (2 H, d, J=8.9 Hz), 4.00 (3 H, s), 2.22 (3 H, s). Two signals due to NH and CO2H were not observed.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 75092-30-7, its application will become more common.
Reference:
Patent; Kawamura, Kiyoshi; Mihara, Sachiko; Nukui, Seiji; Uchida, Chikara; US2003/130277; (2003); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics