Hydrogen Peroxide → HCID 18005394, compound

Participants

Reaction Conditions

Reaction Steps

30% Hydrogen peroxide (1.82 ml) was added to a stirred solution of 1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-5-methyl-4-methylthio-1H-pyrazole-3-carbonitrile (6.2 g) in methanol, containing i-PrOH/H2SO4 catalyst (5.31 ml) described by Drabowicz, et al (above) at 0-5° C. The mixture was allowed to warm to 20° C. over 17 hours. Additional hydrogen peroxide (5.46 ml) was added in three portions over the next 24 hours, along with the catalyst (5 ml). After stirring for a further 60 hours water was added to give 1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-5-methyl-4-methylsulfinyl-1H-pyrazole-3-carbonitrile (6.72 g) as a yellow oil (91.7% area purity by HPLC) having a retention time of 3.61 minutes on a 25.0 centimeter by 4.6 millimeter SUPELCOSIL LC-18 column, eluting with CH3CN/H2O (3:1) solvent at 1 ml/minute.

Provenance & Evidence