| 摘要 |
NEW MATERIAL:A compound shown by the formula I(R is H or lower alkyl; R is halogen, lower alkyl, lower haloalkyl, lower haloalkoxy, nitro, phenoxy or cyano; n is 1 or 2; X is F, Br, I, >=2C lower alkyl, lower haloalkyl, lower haloalkoxy, phenoxy or cyano when n is 1 and X is in the 4-position). EXAMPLE:3-(4-Difluoromethoxyphenyl)-2-isoxazoline-5-carboxylic acid methyl ester. USE:A plant growth regulator especially as a growth regulator and a sterile agent or useful for growth of plants to which they are applied. PREPARATION:A hydroxamic acid chloride shown by the formula III is reacted with an acrylic acid shown by the formula IV or its ester in a solvent such as tetrahydrofuran, etc., in the presence of a base such as triethylamine, etc., at 0 deg.C- the reflux temperature of the reaction solvent to carry out a cyclic addition reaction and to give a compound shown by the formula I.
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