Iodine → 1-Methyl-3-pentafluoroethyl-4-iodo-1H-pyrazole-5-carboxylic acid

Participants

Reaction Steps

1.34 g (2.46 mmol) of ammonium cerium(IV) nitrate and then 0.75 g (2.95 mmol) of iodine are added to a solution of 1.20 g (4.91 mmol) of 1-methyl-3-pentafluoroethyl-1H-pyrazole-5-carboxylic acid in 4.3 ml of acetonitrile and the reaction mixture is heated under reflux for 18 hours. After adding 20 ml of dichloromethane, washing is carried out firstly with water, with sodium disulphite solution and finally with saturated sodium chloride solution. The organic phase is dried over sodium sulphate and the solvent is distilled off at reduced pressure on a rotary evaporator. This gives 1.28 g of 4-iodo-1-methyl-3-pentafluoroethyl-1H-pyrazole-5-carboxylic acid (47%) as an oil.

Provenance & Evidence