Sodium Nitrite → HCID 68387049, compound

Temperature

0 °C

1.00 g (7.34 mmol) of 3-amino-1-ethyl-1H-pyrazole-4-carbonitrile hydrochloride was dissolved in semi-concentrated hydrochloric acid (50 ml), the mixture was cooled to 0° C. and sodium nitrite (532 mg, 7.71 mmol) was added. The mixture formed was stirred at 0° C. for 45 minutes and then added dropwise to a solution, pre-heated to 60° C., of copper(I) chloride (727 mg, 7.34 mmol) in semiconcentrated hydrochloric acid, with evolution of gas. The reaction mixture was stirred at 60° C. for 2 hours, cooled to RT and extracted with CH2Cl2 (3×50 ml). The combined organic phases were dried over Na2SO4, the solvent was removed and the residue was chromatographed on silica gel using the mobile phase dichloromethane/methanol. This gave 630 mg (55%) of 3-chloro-1-ethyl-1H-pyrazole-4-carbonitrile.

1. customThe mixture formed
2. additionadded dropwise to a solution
3. stirringThe reaction mixture was stirred at 60° C. for 2 hours
4. temperaturecooled to RT
5. extractionextracted with CH2Cl2 (3×50 ml)
6. dry with materialThe combined organic phases were dried over Na2SO4
7. customthe solvent was removed
8. customthe residue was chromatographed on silica gel using the mobile phase dichloromethane/methanol

ORD record

ord-437140772d164c1f8be2f3b3f9d8456f

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09078442B2