| 摘要 |
PURPOSE:To obtain a pyridine compound having chlorine at alpha-site, useful as a synthetic raw material for pharmaceuticals, agrochemicals, etc., in high yield and purity by using phosgene as a chlorination agent and chlorinating a pyridine compound having OH at alpha-site with the chlorination agent in an inexpensive inert solvent in the presence of a specific acid amide derivative. CONSTITUTION:A pyridine compound having Cl at alpha-site and expressed by formula TV is produced by chlorinating a pyridine compound having OH at alpha-site and expressed by formula III (R<1> is H, F, Cl, cyano or a 1-4C alkyl) with phosgene in an inert solvent in the presence of an acid amide derivative of formula I or formula II (R<2> to R<4> each is H, an alkyl or an aryl; R<5> is an alkyl or an aryl; n is 1-5). The acid amide derivative of formula I is preferably dialkylformamides and the acid amide derivative of formula II is preferably N-methylpyrrolidone. The starting compound of formula III is 3-cyano-6- hydroxypyridine. The inert solvent is preferably an aromatic hydrocarbon such as benzene and toluene from the viewpoint of yield. The reaction is preferably carried out by using a reaction assistant such as a dialkylformamide. |
