Picoline 3-chloro

Chloro-5-trifluoromethylpyridine, an iatermediate to the herbicide flua2ilop—butyl, can be made from ( -picoline by two processes. ( -Picoline is chloriaated to 2-chloro-5-trichloromethylpyridine [69405-78-9], followed by fluoriaation with hydrogen fluoride under pressure (200°C, 10 h) (441) or vapor-phase (350°C, CCl diluent) conditions (442). An alternative process features the siagle-step vapor-phase reaction of ( -picoline with chiorine—hydrogen fluoride (400°C, N2 or CCl diluent) (443). 

Halopyridines undergo self-quaternization on standing while the less reactive 2-halo isomers do not. However, more is involved here than the relative reactivity at the ring-positions. The reaction rate will depend on the relative riucleophilicity of the attack-ing pyridine-nitrogens (4-chloropyridine is more basic) and on the much lower steric hindrance at the 4-position. Related to this self-quatemization are the reactions of pyridine and picolines as nucleophiles with 4-chloro- and 2-chloro-3-nitropyridines. The 4-isomer (289) is. again the more reactive by 10-30-fold (Table VII, p. 276). 

The total consumption of 2-methylpyridine (a-picoline) in 1980 has been estimated at 12,000 tons [81CI(L)23]. Half is produced for the U.S. market, whereas the demand in both Western Europe and Japan lies between 2000 and 2500 tons per annum. A significant outlet for 2-methylpyridine is in the production of 2-chloro-6-(trichloromethyl)pyri-dine, which is used as a nitrification inhibitor in agricultural chemistry and in the manufacture of the defoliant 4-amino-2,5,6-trichloropicolinic acid. The major commercial outlet for 2-methylpyridine is, however, its use as a starting material for the production of 2-vinylpyridine [Eq.(7)]. 

The hydrolysis at 25 °C of p-nitrophcnyl picolinate (71) catalysed by the Cu(II) complex of 4-chloro-2,6-di(iV-hydroxyethylaminomethyl)phenol (72 R = CH2NH CH2CH2OH) was studied kinetically at different pH in the presence of three surfactants hexadecyltrimethylammonium bromide, sodium lauroylsarcosinate, and polyoxyethylene (23) lauryl ether.69 The Cu(II) complexes of two iV-alkyl-3,5-di(hydroxy-methyl)-1,2,4-triazoles (73 R = CioH2i, Ci2H2s) were better than the Ni(II) complexes as catalysts for the hydrolysis of p-nitrophcnyl picolinate (71) in CTAB micelles.70... 

The light-catalyzed chlorination of 2-picoline with chlorine water is said to involve substitution of the side-chain first, to give 2-trichloro-methylpyridine (11) which, under more vigorous conditions, gives the 5-chloro (12), the 3,5-dichloro (13), and the 3,4,5-trichloro, derivatives (14).40 The side-chain chlorination may well be a homolytic process,... 

CH3 POCI3, 140-150° 4-Chloro-2-picoline (60%) 6-Chloro-2-picoline 2-Picolyl chloride (8%) 342... 

When the adduct of pyridine A-oxide and p-toluenesulfonyl chloride is heated to about 205° one of the products formed is 3-tosyl-oxypyridine.187 The other products isolated are 2,3 -dipyridyl ether, JV-(2 -pyridyl)-2-pyridone, Ar-(2 -pyridyl)-5-chloro-2-pyridone, and A-(2 -pyridyl)-3-chloro-2-pyridone.161 3-Picoline gives, among other compounds, 5-tosyloxy-3-pieoline.353,354 Various mechanisms have been proposed for the formation of the 3-tosyloxy derivative.368-357... 

Several complexes have beeai found to be dimeric. Infrared spectroscopy shows that the CuNCS(L) complexes (L = py, 2- or 4-picoline, 3,5-lutidine, or quinoline) contain bridging thiocyanato groups (332). The mass spectra of CuX P(cyclohexyl)3 complexes (X = Cl, Br, I) show no peaks of higher mass than those corresponding to dimeric molecules, and the far-infrared spectrum of the chloro complex indicates that they are dimeric with halo bridges (248). Triphenylphosphine reacts with copper(I) trifluoroacetate in dichloromethane to give [Cu(02C CF3)(PPh3)]2 which is dimeric in chloroform but partially dissociated in dichlorobenzene (107). 

C6H4FN02 1 -fluoro-4-nitrobenzene 350-46-9 478.15 41.789 1,2 6715 C6H5CIN202 2-chloro-5-nitro-3-picoline 22280-56-4 473.15 41.310 2... 

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