[CH3:1][N:2]=[C:3]=[O:4].[Cl:5][C:6]1[CH:7]=[N:8][N:9]([OH:11])[CH:10]=1>C(#N)C>[CH3:1][NH:2][C:3](=[O:4])[O:11][N:9]1[CH:10]=[C:6]([Cl:5])[CH:7]=[N:8]18 g of methyl isocyanate, dissolved in 50 g of acetonitrile, are added to 15 g of 4-chloro-1-hydroxypyrazole and 150 g of acetonitrile at 25° C., while stirring. Stirring is continued for 12 hours, after which the reaction mixture is evaporated down and the residue is digested 3 times with a total of 150 g of petroleum ether. 17.8 g (80% of theory) or 4-chloropyrazol-1-yl N-methylcarbamate of melting point 125° C. are obtained.
Loading…