Substituted pyrazole compounds and process thereof

摘要

Pyrazole compounds of formula (I), its derivatives, salts, stereoisomers or regioisomers thereof, wherein R1 is selected from SH, SCH2PH, SR or S-SR1 where R is a C1-4alkyl; R1 is a group of formula (II) where * donates the point of attachment; R2 is selected from a straight chain or branched C1-7alkyl which may be optionally substituted by a phenyl group optionally substituted with one or more Cl, Br, F, I, NO2, CN, C1-5alkyl, phenyl or C1-4alkoxy; and R3 is selected from a straight chain or branched alkyl which may be optionally substituted with one or more of Cl, Br, F, I or phenyl, where the phenyl group may be optionally substituted with one or more of Cl, Br, F, I, C1-5alkyl, phenyl or C1-4alkoxy. Compounds of formula (I) are useful as intermediates in the preparation of sulphonamide or sulfonyl urea plant growth regulators or herbicides. Processes for the preparation of pyrazole compounds of formula (I) are also outlined. Compounds exemplified include 1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-thiol; 4-{[5-(1-methyl-5-sulfanyl-1H-pyrazol-4-yl)-2H-tetrazol-2-yl]methyl}benzonitrile; and 1,2-bis(1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazol-5-yl)disulfane.