- 6-chloro-3-fluoro-2-pyridine carboxylic acid synthesis
-
The invention discloses a 6-chlorine-3-fluorine-2-picolinic acid synthesis process. The main starting material is 6-chlorine-3-fluorine-2-methylpyridine.The 6-chlorine-3-fluorine-2-methylpyridine serves as the starting material, dilute sulphuric acid is a solvent, potassium dichromate is an oxidizing agent, sodium tungstate (Na2WO4 2H2O) and crown ether are a composite catalyst, after reaction is completed, a crude product is obtained through conventional post-processing, the crude product is heated to be dissolved in an alkaline aqueous solution, unreacted micro raw materials and other impurities are extracted through an organic solvent, a water layer is acidized through mineral acid, pure 6-chlorine-3-fluorine-2-picolinic acid is obtained after cooling and crystallization are carried out, the yield is high, and the quality of the product is good.
- -
-
-
- Pyridylthio-acylanilide herbicides
-
Novel herbicidally active pyridylthio-acylanilides of the formula STR1 in which R1, R2 and R3, independently of one another, represent hydrogen, halogen, cyano or trifluoromethyl or alkyl, alkoxy and alkylthio having 1 to 4 carbon atoms in each case, R4 represents halogen, methyl or methoxy, n represents a number 0, 1 or 2, z represents the group (Ia) STR2 or the group (Ib) STR3 where X represents oxygen, sulphur, an N--R10 or N--O--R11 group, or X and Rg tpgether represent the STR4 radical, and the other radicals can have various meanings. Intermediates of the formulae STR5 are also new.
- -
-
-
