中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
2-氯代丙烯酸甲酯 | methyl 2-chloroacrylate | 80-63-7 | C4H5ClO2 | 120.535 |
514,619. Organic acids and their derivatives. McLEISH, N., CRAWFORD, J. W: C., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Feb. 10, 1938, Nos. 4264, 5209, and 8051. [Class 2 (iii)] Chlorine-containing organic acids or functional derivatives thereof such as the metal salts, esters and chlorides, are prepared by causing formaldehyde or a polymer thereof to react with trichlorethylene in the presence of sulphuric acid of not less than 80 per cent. concentration, and subsequently heating the reaction mixture to a temperature of at least 80‹ C. and preferably to at least 120‹ C. in the presence of water and (or) an alcohol. A compound COCl.CHCl.CH2HSO4 appears to be first formed, which on gentle heating is converted to an acid or ester still containing the -CH2HSO4 grouping, but on stronger heating gives a hydroxy acid, an unsaturated acid or esters of such acids. If the amount of water present is at least 1.5 times the weight of sulphuric acid, chlorohydracrylic acid is produced, and if the amount of water is less than this, alpha-chloracrylic compounds mainly result, or the chlorohydracrylic acid may be dehydrated to form chloracrylic acid. Esters may be prepared by adding methyl, ethyl, propyl, isopropyl, n-butyl, secondary butyl, n-amyl, benzyl, #-phenyl ethyl alcohol or cyclic alcohols such as cyclohexanol and methyl cyclohexanol. Polymerization of the acids or esters is prevented during reaction by a small amount of resorcinol, hydroquinone, pyrogallol, copper, sulphur or tannic acid. Salts may be prepared by treating the crude acids with oxides, hydroxides or carbonates of sodium, potassium, lithium, barium, strontium, calcium, magnesium, iron, copper, lead, zinc or mercury. Examples are given of the preparation of alpha-chloracrylic acid, its barium salt and its methyl, ethyl, n-propyl, isopropyl and n-butyl esters, alpha-chloracrylic chloride, chlorohydracrylic acid and its ethyl-ester. Methyl-alpha, #-dichloropropionate is also formed in the reactions.