Methyl iodide → HCID 86660093, compound

3.0 g (10.9 mmol) of ethyl 3,4-bis(trifluoromethyl)-1H-pyrazole-5-carboxylate and 4.5 g (32.6 mmol) of potassium carbonate are suspended in 70 ml of acetone, and 1.35 ml of iodomethane (21.7 mmol) are added. The reaction mixture is stirred at room temperature overnight. 54 ml (108 mmol) of 2 N aqueous sodium hydroxide solution are added to the suspension. The solution is then stirred at room temperature overnight. The reaction mixture is diluted with water, and most of the acetone is removed on a rotary evaporator under reduced pressure. The residue is adjusted to pH 2-3 using 1 M hydrochloric acid. The aqueous reaction solution is extracted twice with ethyl acetate. The combined organic phases are dried over magnesium sulphate, filtered and concentrated under reduced pressure on a rotary evaporator. This gives 2.7 g of 1-methyl-3,4-bis(trifluoromethyl)-1H-pyrazole-5-carboxylic acid (84%; purity 88%) as a brown solid.

1. stirringThe solution is then stirred at room temperature overnight
2. custommost of the acetone is removed on a rotary evaporator under reduced pressure
3. extractionThe aqueous reaction solution is extracted twice with ethyl acetate
4. dry with materialThe combined organic phases are dried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure on a rotary evaporator

ORD record

ord-d5becf19761e4e78bbf8ee1ccafbdd64

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09126945B2