SU514802A1 - The method of obtaining dichloro-n-or iso-alkane - Google Patents

Description

(54) METHOD FOR OBTAINING DICHLOR-N-OR ISO-ALKANA

one

The invention relates to methods for producing dichloro-n-or iso-alkane, which are widely used in the industry of basic organic synthesis.

A known method for producing dichloralkanes by the oxidative chlorination of alkenes at a high temperature in the presence of a catalyst.

However, the use of high temperatures leads to contamination of the reaction mass by the reaction byproducts,

Also known; The method for producing dichloroalkanes is low-ohm mous oxide of the oxide by the chlorination of alkenes at 40-1OO ° C.

Chlorination is carried out with a mixture of hydrochloric acid and hydrogen peroxide.

This method involves the use of expensive and scarce peroxide of hydrogen chloride, which is irrevocably spent in the course of the process or in the process of operating in the city. It is necessary to concentrate it as a result of which the process becomes more complex.

In order to improve the technological process, it is proposed to use chromic anhydride as a catalyst and to conduct the process at 20-30 ° C. ; Chromic anhydride during the process remains unchanged,

I The oxychlorination was carried out in a 4-Roral I flask equipped with a stirrer with a mercury after JTBOpoM contact thermometer, two: gas supply tubes and a reverse

ball fridge. The flask is immersed in a water bath. ; The reaction proceeds according to the scheme;

h:

Example 1. In a reaction flask are placed 61.05 g (0.5 mol) of a 30% i solution of hydrochloric acid and 0.91 g:

(0, O091 mol) of chromic anhydride / When; 20 ° C to the reaction mass, with a flow of 3 l / chao, propylene in the amount of 1 10.5 O g (0.25 mol) and oxygen with a sko-; a growth rate of 2.8 l / h in a volume of 6.10 g j (0.2 mol). After passing the given |

The yield of dichloropropac 56.5% of the theoretical is recalculated sprout propylene With a selectivity of 83.4%.

Example 2. 81 g (1 mol) of a ZO% hydrochloric acid solution and 1.2 g (O, O12 mol of phosphoric anhydride) are placed in a rea1Sh8ov11 flask. At 2 ° C, a mass of 11.9 ml is fed into the reaction / an hour of isoamylenes in the amount of 23.3 R (O, 5 mol) and kilor-speed with a speed

the amount of propylene stirring the reaction mass is continued for 1 hour. The reaction product is separated from the acidic layer, neutralized with a 4% soda solution, dried over calcium chloride, and then analyzed on a chromatograph.

Material balance

the experience is given in table. one.

Table 1.

78.7

78.3.

2.8 l / h in the amount of 12.1 g (0.37 mol). After passing a specified amount of isoamylenes, stirring is continued for 1 hour, then the product is separated; /, from the acidic layer, neutralize from i soda solution, dry, and. Is ana lysed.

The material hint of experience is given in b. tab. 2

The yield of dichlorisopentane from the theoretical in terms of the initial isoamylene is 73% with a selectivity of 90.8%, t

Claims (1)

Invention Formula Crystallization of dichloro-n-or iso-alkane by oxidative chlorination in Table 2 117.6 117.6 the corresponding alkene in the presence of hydrochloric acid and catalyst, tl i-: due to the fact that, in order to "improve" the process, a catalyst is used chromic anhydride and the process is carried out at 20-30 ° C.