Methyl Isocyanate → 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-methylsulfinyl-1H-pyrazole-3-carboxaldehyde O-(N-methylcarbamoyl)oxime

Participants

Reaction Steps

A mixture of 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-methylsulfinyl-1H-pyrazole-3-carboxaldehyde oxime (1.5 g), methyl isocyanate (0.705 g), and dibutyltin diacetate (2 drops) was stirred in dichloromethane at 20° C. in a sealed bottle for 2 days. The mixture was partitioned between water and dichloromethane, the organic layer dried (Na2SO4) and evaporated and the residue crystallized from ethyl acetate/hexane to give 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-methylsulfinyl-1H-pyrazole-3-carboxaldehyde O-(N-methylcarbamoyl)oxime (1.22 g) m.p. 146-147° C. Compound 18.

Provenance & Evidence