| 摘要 |
1361224 Phosphorus-containing esters of substituted hydroxy pyridines PEPRO SOC POUR LE DEVELOPPEMENT ET LAVENTE DE SPECIALITES CHIMIQUES 30 June 1971 [30 June 1970] 30661/71 Headings C2P and C2C The invention comprises esters of the general formula wherein R 1 is a C 1 -C 4 alkyl or -alkoxy radical or a halogenoalkyl, alkylamino, dialkylamino, phenyl or phenoxy radical, R 2 is a C 1 -C 4 alkyl or -haloalkyl radical, R 3 and R 4 which may be the same or different are selected from H, halogen (e.g. Cl, Br or I), NO 2 or CN but cannot both be hydrogen, and X is O or S. They may be obtained by reacting a chloride of the formula (R 1 )P(X)(OR 2 )Cl with an appropriately substituted 3-hydroxy-6-methyl pyridine in the presence of a hydrohalic acid acceptor or with a salt of the hydroxy pyridine derivative. The products have insecticidal, acaricidal and nematocidal properties and may be used as active ingredients in conventional pesticidal compositions. 2 - Chloro - 3 - hydroxy - 6 - methyl - pyridine is obtained by reacting phosphorus pentachloride with 2-nitro-3-hydroxy-6-methyl-pyridine in suspension in POCl 3 . 2-Bromo-3-hydroxy- 6-methyl-pyridine is obtained by the action of bromine in solution in pyridine or 3-hydroxy-6- methyl-pyridine also in solution in pyridine. 2 - lodo - 3 - hydroxy - 6 - methyl - pyridine is obtained by treating a suspension of 3-hydroxy- 6-methyl-pyridine in distilled water containing sodium carbonate with iodine dissolved in water by means of KI. 2-Chloro-3-hydroxy-4-nitro-6- methyl-pyridine is obtained by the action of red fuming HNO 3 on 2-chloro-3-hydroxy-6-methylpyridine dissolved in strong H 2 SO 4 , and 2,4- dichloro - 3 - hydroxy - 6 - methyl - pyridine is obtained by portion-wise addition of PCl 5 to a solution of 2-chloro-3-hydroxy-4-nitro-6-methylpyridine in POCl 3 . |
