| 摘要 |
NEW MATERIAL:The compound of formula I (R<1> is H or lower alkyl; R<2> is H or lower alkyl; R<3> is lower alkyl). EXAMPLE:5-t-Butylthio-4-ethoxycarbonyl-1-methylpyrazole. USE:An intermediate for pharmaceuticals and agricultural chemicals and production intermediate for chlorosulfonyl pyrazole derivative of formula II. PREPARATION:The objective compound of formula I can be produced by mixing an aminopyrazole derivative of formula III with di-t-butyl disulfide, adding a nitrous acid source (e.g. alkyl nitrite, nitrogen trioxide, nitrogen monoxide, nitrosyl chloride, etc.) and stirring at 90-110 deg.C for 15min-2hr. The compound of formula II is obtained by dissolving or suspending the compound of formula I in an inert solvent system such as water, dilute hydrochloric acid, water- chloroform mixture, etc., and reacting with Cl2 at 0-20 deg.C. |
