NEW MATERIAL:A pyrazole-4-carboxylic acid derivative shown by formula I (R1 is 1W8C alkyl, fluoroalkyl, allyl, haloallyl or methylcarbamoyl; R2 is H, 1W3C alkyl, fluoroalkyl or phenyl: with the proviso that a case where R1 an R2 are both methyl group is omitted).
EXAMPLE: 1,3-Dimethylpyrazole-4-carboxylic acid.
USE: Useful as an intermediate for agricultural and horticultural fungicide and an intermediate for a pyrazole derivative having excellently and widely controlling effects on plant blights, especially preventing and treating effects on late blight and downy mildew of various kinds of crops.
PREPARATION: A hydrazine shown by formula 11 is reacted with an ethoxymethyleneacylacetic acid ester shown by formula III (R is lower alkyl) and the reaction product, a compound shown by formula IV, is hydrolyzed to give a compound shown by formula I.
YAMAZAKI HIDEO
KUWAZUKA TOSHIAKI
SHIMOTORI HITOSHI
TANAKA YOSHINORI
ISHIKAWA KATSUTOSHI
| US4245106A | 1981-01-13 |