SU914553A1 - Process for producing thiocarbamates - Google Patents

Description

The invention relates to an improved method for producing thiocarbamates of the general formula

Pic (5) IC 'K ", [1]

where B is alkyl C * - Su normal

or isostructures;

K '- hydroxyethyl, allyl or alkyl

“^ 1,’

K "is hydrogen or alkyl C ₁ - C *.

Thiocarbamates are used as reagents - collectors in the flotation of non-ferrous metal ores.

A known method of producing Ν- (alkyl, - allyl, cyclohexyl, phenyl) -O-alkylthylcarbamate, which consists in the interaction of the amine and xanthic acid derivative - bis (alkylxanthogen) sulfide of the general formula

. NOSE (5) - 5 _X - (5) CSC, where K is alkyl C, - C _c ;

X from 1 to 4.

The main disadvantage of this method is the use of bis- (alkylxanthine) sulfides, which, in turn, are obtained from alkali metal xanthates, which makes the process uneconomical. For example, the average cost of 1 ton of bisalkylxantogen disulfide is 3 ~ 3.5 times higher than the corresponding xanthate.

The closest to the invention to the technical essence and the achieved result is a method of obtaining 0, H-dialkylthiocarbamate by the interaction of alkylamine with alkali metal xanthate in an aqueous medium at 50-90 C in the presence of a catalyst, such as platinum or paladium [23.

However, this method has a significant consumption of raw materials, the duration of the process, the use of reagents with high corrosive ability.

The purpose of the invention is the simplification of ⁴

Cessa.

9H553 '

This goal is achieved by a method of obtaining thiocarbamates of General formula I, consisting in the interaction of alkylamine with alkali metal xanthate in an aqueous medium in the presence of a catalyst - a polysulfide of the formula

(K ¹ 8 'ΝΗ), 5 {

> 2. ^er 8 '

where b and b

has the above value at 70-75 ^ 0.

Technology method is as follows.

Alkali metal alkylxanthate, amine, catalyst are loaded and the process is carried out at 70-75 for 2.5-3 hours. The catalyst is prepared by heating the calculated amount of amine with sulfur, respectively. The yield of the target product is not less than 95%. The catalyst is added in an amount of 0.1-0.15 mol per 1 mole of xanthate.

EXAMPLE 1. To 69.6 g (0.4 mol) of isopropyl potassium xanthate, add 24.8 g (0.8 g mol) of monomethylamine, 200 ml of water, and 25.74 g (0.08 g). Mr. molp) catalyst (k'-CH ^, Β ^{/ Ζ} = Η) and stirred at 70-75 C ⁱⁿ 3 hours. After cooling and separation, the obtained 51.6 g (97%) Ν-methyl-0-izopropiltiokarbamata . Content of the main substance is 93.5%. After distillation in vacuum, pure чистый-methyl-O-isopropylthiocarbamate has a bp. 90-91 ° C.

PRI mme R 2. The process is carried out as described above, but instead of monomethyl · use _on monobutylamine. 0.1 g of 0.1 g mol of polysulfide is charged as a catalyst, where B ¹ =

ScN _e , HS "= H. Get 67, .41 g (9b, 3%) of Ν-butyl-O-isopropylthiocarbamate with a bp 87" 88 ° C.

for example The reaction is carried out using potassium isobutyl xanthate. As a catalyst, 0.12 gmol of polysulfide is used (where B = CH 3, B = 0). Get 71,84 g (95,0%) Ν-dimethyl-Oisobutylthiocarbamate, with so pl. 2829 ° C.

PRI me R 4. The reaction is carried out analogously to example 1 using n-propyl potassium xanthate and allylamine. The catalyst used is 0.14 g-mol of polysulfide (where B ¹ is allyl, 8 ”= H). Get 66,85 g (98,96%)-allyl-O45

50

55

-propylthiocarbamate with bp. 119 “

<0

15

20

25

3 (

20

121 ° C / 12 mmHg

= 1.5120,

, 018.

PRI me R 5. The reaction is carried out analogously to example 1 using potassium isopropyl xanthate and ethanolamine. The catalyst used is 0.15 gmol of polysulfide (where b '= CH ₂ CH _g 0H, c = H). 57.698 g (97%) of Ν-hydroxyethyl-Oisopropylthiocarbamate are obtained with a bp of 124126 C / mm Hg .st.

Example The reaction of n-butyl potassium xanthate is carried out with ethanolamine as described above. Polysulfide is used as a catalyst (where B * = CH ₂ CH, OH, B ^P = H). 67.47 g (97.3%) of Ν-hydroxyethyl-O-butylthiocarbamate are obtained, with a bp of 144148 ° / 1 mm Hg.

PRI me R 7. The reaction is carried out analogously to example 5 using both oamyl xanthate and ethanolamine. Polysulfide (where B · = CH ^ CH ^ OH c "= H) is used as a catalyst. 18.6 g (97.9%) of 0-isoamyl-M-hydroxyethylthiocarbamate, st. Bp 145 ~ 153 ° C, are obtained. / 1 mm Hg

Example The reaction is carried out using potassium n-propyl xanthate and diethylamine as described in example 2. Polysulfide is used as a catalyst (where B ¹ = C ₂ H $, c = C ₂ H ₅ ). Get 17.02 g (96.9% ) Onn-propyl-M-diethylthiocarbamate with a melting point of 35 ° C.

PRI me R 9 · Preparation of ί mole of catalyst.

K 1 I pray the amine of the general formula

40

b'β "νη,

In ^G- alkyl C-Sc normalizing, alil or oxide "- alkyl or K, load

Where

foot or alkyl, and

1 mole of sulfur and stirred at 45 “

50 ° C, so that sulfur with the amine completely reacted. The end of the reaction is determined by the disappearance of the sulfur precipitate and the solution staining in an orange-yellow color characteristic of the above polysulfides. The finished catalyst used in the preparation of thiocarbamates specified in examples 1-6 quantities. Per mole of xanthate load from 0.2 to 0.375 moles of catalyst.

Thus, the proposed method is an industrial method.

obtain thiocarbamate and economically · more profitable.

5 914553

Claims (1)

The method of obtaining thiocarbamates general formula! ’CBS ^ NK 'K" where K is alkyl C ₂ - C $ · normal 5 or isostructures; K-oxyethyl, allyl or alkyl D is hydrogen or alkyl C ^ - C _g , by reacting an alkylamine with an "0 alkali metal xanthate in an aqueous medium at 70 ° C 75 ° C, in the presence of a catalyst, I distinguish due to the fact that, in order to simplify the process, polysulfide of the formula , (κ '^ ΝΗ) ^ where b and k have the above values.