SU1060101A3 - Process for producing 1-chlorohexane - Google Patents

Abstract

METHOD OF OBTAINING 1-CHLOREGEXANE by reacting 1-hexanol with an excess of a solution of concentrated hydrochloric acid in the presence of a phosphonium catalyst, differing from the fact that, in order to simplify the process, a phosphonium catalyst obtained by reacting tributylphosphine with chloromethylated, containing 1, is used as a catalyst , 2 - 1.3 mg-eq of chlorine with polystyrene resin with 1% cross-linking, taken in an amount of 30-32% by weight of 1-hexanol.

Description

The invention relates to a method for producing 1-chlorhexane used as an intermediate for the synthesis of compounds of various classes, primarily amines and nitriles, mercaptans.

A known method of producing primary chloralkyls, including 1-chlorhexane, by liquid-phase hydrochlorination of alcohols with hydrogen chloride or concentrated hydrochloric acid in the presence of catalysts - chlorides of zinc, copper, bismuth, mercury, tin [1J.

The disadvantages of the method include the use of large (up to equimolar with respect to alcohol) amounts of catalyst, the difficulty of separating the catalyst from the reaction mixture and the formation of by-products, especially esters.

Closest to the proposed technical essence and the achieved result is a method for producing 1-chlorhexane by reacting 1-hexanol in excess. (1.5 - 10 mol per mol of 1-hexanol) solution of concentrated hydrochloric acid in the presence of a phosphonium catalyst, which is hexabutylphosphonium bromide. The process at 105 ° C for 30 and 45 h leads to the conversion of 1-hexanol to chlorhexane 87 and 95%, respectively, the formation of by-products does not occur [2].

The disadvantage of this method is the difficulty of separating phosphonium. catalyst in solution; the state from the reaction mixture, which complicates the process technology by introducing additional stages of concentration, separation or transfer of the catalyst into a less reaction form.

The purpose of the invention is the simplification of process technology.

This goal is achieved in that according to the method for producing 1-chlorhexane by reacting 1-hexanol with an excess (10 mol per mol of 1-hexanol) of a solution of concentrated hydrochloric acid in the presence of a phosphonium catalyst, a phosphonium catalyst obtained by reacting tributylphosphine with chloromethylated is used as a catalyst containing 1.2 - 1.3 mEq chlorine polystyrene resin with 1% cross-link, taken in an amount of 3032% by weight of 1-hexanol.

The use in the process of a phosphonium catalyst deposited on a polystyrene resin representing VNIIIPI Order 9868/60 Circulation 418 Subscription Branch hntf ^ patent, Uzhgorod, 4, Proektnaya St., 4th phase, a solid phase, facilitates the separation of the phosphonium catalyst from the reaction mixture.

Example 1. In a flask with a volume of l load 50 g of chloromethylated polystyrene resin with 1% cross-links containing 1.24 mEq of chlorine per gram of resin, 500 ml of dimethylformamide and 16.2 g (0.08 mol) of tributylphosphine. Mixture

Yu is heated with stirring for 4 hours at 120-130 ° C. Then the mixture is cooled to 70 ° C, filtered while hot and the product is washed successively three times with dimethylformamide and three times with acetone. The product is dried in a vacuum dryer at 100 ° C. and 69.4 g of a phosphonium catalyst are obtained.

Example 2. In a flask with a volume of l load 103 g (1 mol) of 1-hexanol, 32.3 g (31 wt.% With respect to 1. Hexanol) of the phosphonium catalyst obtained in example 1, 500 ml of concentrated hydrochloric acid (10 mol HC1) and a small amount of metal chips (for better boiling). A reflux condenser was added and the mixture was refluxed for 43 hours with slow stirring. Then the mixture is cooled ₍ and the phosphonium catalyst is filtered off from the reaction mixture. The organic layer is separated from the water phase, the basics on a separatory funnel. Received

e- ⁵ 'in an amount of 54.0 g, the organic layer is, according to chromatography exclusively 1-chlorhexane.

Water: the layer is separated and analyzed for the content of hydrogen chloride •, the amount of which is 9.1 mol.

The phosphonium catalyst is washed • with a mixture of water and methylene chloride, the obtained organic layer is separated from the aqueous, methylene chloride is distilled from it in a hot water bath at 50 ° C. After distillation, the organic layer contains 59.1 g of 1-chlorhexane.

The total amount of 1-chlorhexane obtained is 113.1 g (0.94 mol), which is 93.7% of the theoretically possible.

Using the proposed method for producing 1-chlorhexane greatly simplifies its production technology from 1-hexanol due to the use of a solid phosphonium catalyst in the process, which is easily separated from the reaction mixture. Simplification of the technology will increase the production of 1-chlorhexane for the synthesis of compounds of various classes, primarily amines nitriles, mercaptans.

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Claims (1)

METHOD FOR PRODUCING 1-CHLORHEXANE by reacting 1-hexanol with an excess of a concentrated hydrochloric acid solution in the presence of a phosphonium catalyst, characterized in that, in order to simplify the process technology, a phosphonium catalyst obtained by reacting tributylphosphine with chloromethylated 1 containing 2 - 1.3 mEq of chlorine with a polystyrene resin with 1% cross-links, taken in an amount of 30 - 32% by weight of 1-hexanol. In and > 1 1060101