SU639875A1 - Method of obtaining higher alkylmercaptans - Google Patents

Description

three types. Thus, the presence of frequencies of 835 and 3015 cl indicates the existence of three-substituted double bonds, the frequencies at 890 and 3085 correspond to methylene groups (C CH2), and three frequencies at 920, 1000 and 3085 cm refer to vinyl groups (-CH CH2) . Judgment on the intensity of the absorption bands, most of the oligomers obtained

a) the formation of propylene trimers and the synthesis of mercaptans

 / TiCl -bEACClz

propylene occurs on (hydrocarbons containing methylene and vinyl groups. This fact determines the high activity of oligomers in the addition reaction of hydrogen sulfide.

Thus, these transformations can be represented by the following general schemes:

 H2 S

.one

.... ..J-

c) the formation of pentamers and synthescapher

TiCb + TlAlCij,. 1 F i L 5

... ..AJ ii / - xXXxC

$ Vi

Example 1. A 1-liter steel reactor, equipped with a heating jacket, a stirrer, devices for chasing and withdrawing liquid and gaseous reactants, is evacuated and purged with pure nitrogen. In the current of the latter, a solution of the catalyst obtained by adding 1.26 g of ethyl aluminum dichloride into a solution of 0.3 g of titanium tetrachloride in 30 ml of propylene tetramers (industrial product) is introduced into the reactor at 0 ° C and stirring for 30 minutes. After loading the catalyst into the reactor, propylene (200 g) is injected and the temperature in the jacket is raised to 120 ° C with the help of heat carrier. The contents of the nepeMeninBrd reactor are kept at this temperature for 3 hours, after which the reactor is gradually cooled to a temperature of .. 10 ° C and unreacted propylene is released in a gas clock. A small part of the oligomerizate is selected to determine the composition, and the rest is used for the synthesis of mercaptans. From the part of the oligomerizate selected for analysis, after decomposition of the catalyst and distillation in vacuum, three fractions were obtained.

I fraction: t. Cues. 120-150 ° C; SG 835, 3015 (trans

-P

spectrum

cm

 C weak band, characteristic of trisubstituted double bond), 890, 3085 (CC CH2, methylene), 920, 1000, 3085 (CH CH2, vinyl terminal); molecular weight 126, which corresponds to propylene trimers; The average degree of unsaturation is 1 (titration of Brj in acetic acid).

II fraction: so ktsh. 150-275 ° C; IR spectrum (v, c.i.r-): 890, 3С85 С СН2, methylene), 920, 1000, 3085 (-СН СН2, vinyl terminus); molecular weight 168, which corresponds to propylene tetramers; The average degree of pegs is equal to 1. Along with propylene tetramers, fraction I contains a small amount (-8%) of propylene pentamers with a molecular weight of 210.

III fraction (residue): m. Bale. 280 ° C; IR spectrum (V, CU-): 835, 3020 (-CH CH Three-substituted double bond), 920, 1000, 3085 (-CH CH2, winnine); molecular weight in the range of 210-294, which corresponds to propylene oligomers with 5-7 units of propylene; The average degree of unsaturation is 1.

Through the oligomerizate in the reactor (the yield of olgomers is 90%, the average molecular weight is about 170. which corresponds to propylene tetramers) with the help of a special input, a current of dry hydrogen sulfide in the amount of 2 moles per mole of olefin and temperature of 20 ° C is passed for 1.5 hours. the end of the reaction, the mixture is freed from non-reacted hydrogen sulfide by blowing nitrogen. The product is washed with water, an aqueous solution of soda, again with water and dried with calcium chloride, iol (211 g of the product with a mercaptan sulfur content of 13.67% (silver titrated with silver nitrate) is taken into account, which corresponds to 86.5% yield of the highest mercaptan gross formula Ci2H2.-.SH based on propylene oligomers. The average molecular weight of mercaptan 200 (cryoscopic method in benzene). The data on propylene oligomerization and the synthesis of mercaptan, according to example I, are summarized in table (experiment 1).

When measuring the temperature of the reaction of propylene oligomers with hydrogen sulfide in the range of ~ 50 ° C, the yield of higher mercaptan varies in the range of 84–92%. 1-1 Changing the rate of hydrogen sulfide iropus (2 mol per 1 hour or 3 hours) has little effect on the output of higher merkaitia.

Example 2. The order of propylene oligomerization and the subsequent reaction with hydrogen sulfide is similar to Example 1. The difference is that the temperature is 1: the homeization is maintained at 80-60 ° C, respectively, yields are obtained for propylene oligomers G5 and 52% the average molecular weight of which corresponds to tetramers, and the degree of height increase 1. The data on oligomerization and the synthesis of mercaptans are presented in Table 1; e (experiments 2 and 3).

Example 3: Order of oligomerization and subsequent reaction with hydrogen sulfide is similar to Example 1. The difference is that 2.5 g, A1C12, is used to prepare the catalyst. The oligomerization temperatures are 120 and 80 ° С, respectively. For 3 h, yields of propylene oligomers are obtained, close to 100%. The molecular weight of oligomers is 160. The degree of unsaturation is 1. The data on oligomerization and the synthesis of mercaptans are presented in the table (experiments 4 and 5).

EXAMPLE 4 The order of carrying out oligomerization and the subsequent reaction with hydrogen sulfide is similar to Example 1. The difference is that 10 g of C2H, -, A1C12 are taken for the preparation of a catalyst. Temierature

oligomerization 120 and 80 ° C, respectively. In 3 hours, close to 100% yield of oligomers is obtained, the average molecular weight of which (210) corresponds to propylene pentamers. Average degree of unsaturation

ravia longhomers 1.

Upon reaction with P25, the higher mercaptan of the gross formula Ci .-. HsiSn was obtained. Data on solubilization and mercaptan are presented in the table (experiments 6 and 7).

Example 5. The procedure carried out is similar to that described in Example 1. It is excellent in that, instead of -AiCl2 D-1I, preparation is catalytic: oro of the complex, isobutylaluminum HCl in an amount of 1.26 g is used (the amount of TiCU 0 , 3 g). The oligomerization is carried out at 80 ° C for 5 hours. The yield of oligomers (nrenmally tetramers with wall saturation equal to 1) is 87.5%. Under the conditions of reaction with H2S under the conditions described in Example 1, a product was obtained with contents of mercaptan sulfur 13.1%, which corresponds to 82.3% yield of the highest mercaptan gross formula C: 2H2sSIi per oligomer. The data on the oligomercation and synthesis of mercaptans are in the table (experiment 8).

Primer S. Order procedure. the recipe and order of catalyst preparation are similar to those described in irimer 1. It is excellent in that, instead of propylene, the propane-propylene fraction is used for oligomerization,

containing 77% propylene, 17% ironon and; 1sbolt-Sh1e amounts of ethylene, ethane and butane ;. After conducting the reaction of oligomaspone at 20 ° C for 3 h, iol en olgomerizate with a yield of 76% (in the calculation of the figure and massed raw material), and the figure is: approximately equal mixtures of tri- and tetramers of propylene with medium Hg - r-t : -, 5g pepsi-dnostm 1. After the reaction, the resulting oligomer with H2S

Ppo; 5i x, described by L: example 1, obtained 131 g of higher mercaptan (yield about 74%; based on propylene olgaomers) of the gross formula CsNg33H with mercaptan sulfur content of 12.8%. The molecular weight of the product is 190. Linear oligomerization of propylene and synthesis of higher

Instead of C2H5A1CI2, iso-C4H9A1C12 was used.

 Relative transmission constants via RSH i | (1.8-2) 10

through gret-dodecylmercaptan 1.6-10

Claims (2)

1. A method of producing higher alkyl mercaptans from propylene oligomers of CD-21 and hydrogen sulfide in the presence of an alkyl aluminum dichloride catalyst of the formula RAlCb, where R is alkyl of C- € 4, characterized in that, in order to simplify the process, oligomerization of propylene and subsequent direct interaction of oligomers propylene with hydrogen sulfide is carried out on a single catalyst, for which an aluminum-aluminum dichloride – titanium tetrachloride system is used. t-2 2. A method according to claim 1, characterized in that the oligomerization of propylene is carried out at a temperature of 60-120 ° C, and the interaction of propylene oligomers with hydrogen sulfide at O-50 ° C. Sources of information taken into account in the examination: 1. Auth. St. USSR N ° 218167, cl. C 07 C 149/06, 1968. 2. Auth. St. USSR № 518489, cl. C 07 C 149/06, 1974 (prototype). j mercaptans on catalyst TiCb-CjHsAlCI