- Practical synthesis of (6-chloro-3-pyridyl)methylamine by highly selective hydrogenation of 6-chloro-3-pyridinecarbonitrile with improved Raney nickel catalyst
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A practical synthesis of (6-chloro-3-pyridyl)methylamine (1), one of the key intermediates of neo-nicotinoid insecticides, by a highly selective hydrogenation of 6-chloro-3-pyridinecarbonitrile (4) is described. The use of an improved Raney nickel catalyst, prepared from an alloy of low nickel content (Ni 38%, A1 62%) and subjected to heat treatment in water (98 °C, 2 h) after leaching of aluminum, was highly effective for the selective hydrogenation of 4. The hydrogenation of 4 using this catalyst was carried out in EtOH-H2O [6:1 (v/v)] and NH3 at 50 °C and 1.2-1.4 kg cm-2 hydrogen pressure to give 1 in 86% yield and 3-pyridylmethylamine, a dechlorinated by-product, in 2% yield.
- Tanaka, Ken,Nagasawa, Minoru,Sakamura, Hideki
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- Highly selective hydrogenation of 2-chloro-5-cyanopyridine with an improved sponge nickel catalyst
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A practical synthesis of (6-chloropyridin-3-yl)methylamine (1), a key intermediate of neo-nicotinoide insecticides 2, was achieved by highly selective hydrogenation of 2-chloro-5-cyanopyridine (3). The hydrogenation of 3 with an improved Sponge nickel catalyst, prepared from an alloy of low nickel content (Ni 38%, Al 62%) and subjected to heat treatment in water, was carried out at 50°C and 1.2-1.4 kg/cm2 hydrogen pressure to give 1 in 86% yield and (pyridin-3-yl)methylamine (4), a dechlorinated by-product, in only 2% yield.
- Tanaka, Ken,Nagasawa, Minoru,Kasuga, Yuzo,Sakamura, Hideki,Takuma, Yuki,Iwatani, Katsuyoshi
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- Photocatalytic degradation of imidacloprid by phosphotungstic acid supported on a mesoporous sieve MCM-41
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Solid catalysts consisting of polyoxometalates (POM) namely phosphotungstic acid H3PW12O40 (HPW) supported on a mesoporous sieve MCM-41 have been prepared and characterized by FT-IR, X-ray diffraction, nitrogen adsorption and high resolution transmission electron microscope (HRTEM). The HPW/MCM-41 with different HPW loadings from 10 to 60 wt% possess large specific surface area and rather uniform mesopores. Keggin structure of HPW retains on the prepared composite catalysts. The photocatalytic performance of HPW/MCM-41 was examined by degradation of a durable pesticide imidacloprid. It is found that the prepared photocatalysts exhibit high activity under irradiation of 365 nm monochromatic light. For 50 mL of imidacloprid (10 mg/L), conversion of imidacloprid using 20 mg of HPW/MCM-41 with 50 wt% loading level and calcined at 300°C reaches 58.0% after 5 h irradiation. Copyright
- Feng, Changgen,Li, Yanzhou,Liu, Xia
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experimental part
p. 127 - 132
(2012/03/09)
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