IL34486A - The preparation of mercaptans - Google Patents

Description

The of CHEMICAL The reaction of hydrogen sulfide with a hydrocarbon or substituted hydrocarbon having at least one olefinic linkage is accomplished by reacting hydrogen and hydrocarbon the presence of a trivalent organic phosphorus compound as the sole The reaction of hydrogen sulfide with hydrocarbons containing an olefinic linkage is well known in the The reaction of hydrogen with yields primary and sulfides In order to achieve arkownikoff reaction an initiator is Many initiator systems have been employed and are well known in the Various azo compounds been alone and together with water and other promoters to bring about this likewise various peroxides and alone and ogether with promoters like those named also the la the reaction or the energy at a frequency which initiates Detailed Description of the Invention anti It has now been discovered that the koff reaction of hydrogen sulfide with an olefin can be achieved by reacting the hydrogen sulfide and olefin together in the presence of an initiator consisting essentially of a trivalent organic phosphorus That is to the trivalent organic phosphorus compound is present as the sole The mercaptans and sulfides produced by the process of the present invention have wide utility as raw materials for making rubber vulcanizers and anti The present invention is directed to the koff reaction of hydrogen sulfide with an olefin as opposed to the arkownikoff In the ionic or catalyzed addition across the olefinic linkage takes place in accordance with the Markownikoff addition in which the sulfhydryl radical attaches to the unsaturated carbon atom having the lesser number of hydrogen 3 or addition takes that is the sulfhydryl radical attaches to the unsaturated carbon atom having the most hydrogen atoms attached For when an is reacted under acid catalyzed a secondary namely a is in the process of the present the is converted to a primary namely a The primary can then attack another olefin molecule to give the primary In accordance with the present invention there is provided a process which comprises reacting hydrogen sulfide with an wherein said is selected from the group consisting of vinylcyclohexane h the substituted derivatives of said wherein the substituents are selected from the group oonsleting of tertiary carboxylic trivalent phosphorus and pentavalent phosphorus groups or 4 olefins having inert attached directly to the olefinic carbon selected from the group consisting of and ca and an initiator consisting essentially of a trivalent organic phosphorus compound the formula Y and Z are each chalcogen having an atomic weight between 15 and b and c are each equal to 0 or 1 and and are each a hydrocarbon radical having from 1 to 20 carbon trivalent phosphorus being present in an amount from about to about 1 mole per mole of olefinic at a temperature in the from about to about reaction the present invention can be carried out with or without a I the trivalent organic phosphorus compounds used as sole initiator in the process of the invention hydrocarbon radicals can each be or In the preferred embodiment of this b and c are to 1 and are lowe alkyl to 4 carbon atoms or aryl having 6 to carbon These compounds are illustrated by the alkyl aryl phosphonites and phosphinites such 1 tributyl trimethyl tributyl trihexyl tritolyl dimethyl methyl diphenyl phenyl diethyl methyl dimethyl butyl In the process of the present an olefin compound having at least one olefinic linkage is It may however contain two or more olefinic for isoprene or the like can be the olefin must contain at least one olefinic linkage in the aliphatic or cycloaliphatic grouping as distinct from the unsaturated linkage in an aromatic molecule such as This invention is particularly useful for the manufacture of primary mercaptans and sulfides from For can be converted in high yield to and and can be converted to and and and sulfide having from carbon atoms can be converted to their corresponding primary mercaptans and In addition to the described olefins having inert groups attached directly to the olefinic carbon atoms can be employed the present These inert groups can be Illustrated carboxyl and carboxylate both the acrylic which the olefinic carbon atom is linked to the carboxyl carbon and the vinyl in which the olefinic carbon atom is linked to an oxygen atom of the carboxyl and the Examples of this type of compound vinyl vinyl phenyl ethyl methyl vinyl divinyl acrylic The reaction of the present invention can be conducted with or without a diluent The diluent should be inert with respect to the reactants and Suitable diluents include saturated and aromatic hydrocarbons These diluents can be illustrated by toluene and The amount of trivalent phosphorus compound used in the present invention is in the range from about to about 1 mole of phosphorus compound per mole of olefinic linkage The preferred range for the present invention is from about to about mole of phosphorus compound mole of olefinic linkage The hydrogen should be present in an amount in the range from about 1 to about 20 moles of hydrogen sulfide per mole of olefinic The higher the hydrogen sulfide to olefin the higher to ratio going to be in the products The reaction can be conducted over a wide range of temperatures Normally the reaction temperature will be in the range from about to about In the preferred embodiment of the present temperatures in the range from about to about are The reaction can be run in a batch a continuous or in a series of For all the hydrogen olefin and initiators can be added at once or the olefin and hydrogen sulfide can be added as separate streams to a continuous reactor system with an appropriate addition of the initiator in the proper either separately or along with the olefin or hydrogen If a coil reactor can also be employed with injection of the initiator along the coil at ious points As another embodiment of the present the trivalent phosphorus promoters can be generated in situ by adding phosphine to the ole to the trivalent organic phosphorus compounds which can then act as the The following examples further illustrate the practice of the present Example I is the control employing no EXAMPLE I 50 milliliters of benzene were placed in a stainless steel autoclave equipped with a gas thermocouple and a rupture disc assembly rate at 2000 The autoclave was then sealed and evacuated evacuation was shown to be not it insured against the presence of some eign substance which might affect the traces After cooling the autoclave in a nitrogen 0 mole of ethylene and 1 mole of hydrogen sulfide were charged to the The autoclave was heated to 90 and this temperature was maintained for The reaction mixture was then cooled to and was analyzed with a gas using a 12 by coil column taining on mesh Analysis showed that virtually none of the ethylene had EXAMPLE II 1 grams of trimethyl phosphite and milliliters of benzene were placed in an autoclave equipped as in Example The autoclave was sealed and After cooling the autoclave in a nitrogen 0 mole of ethylene and 1 mole of hydrogen sulfide were charged to the The autoclave was then heated analyzed as Example Analysis showed that of the ethylene had been of the initial ethylene was converted to ethyl mercaptan and of it was converted to diethyl EXAMPLE III Using the same method that was employed in Example grams of trlmethyl phosphite was employed as the initiator and moles of propylene was substituted for the The analytical results showed that of the propylene had been converted yielding The mercaptan to sulfide ratio was 1 EXAMPLE IV Using grams of tributyl phosphine as the initiator and mole of the same process as Example II was carried The conversion of the olefin was and the yield of mercaptan was 3 of the initial Other examples were run using the same method moles of propylene was employed as the The results of these examples are contained in Table TABLE I Amount of Example Conversion Yield of Number Promoter Used of Olefin V tributyl phosphine VI triethyl phosphite VII triphenyl phosphite 0 16 tributyl phosphite 9 insufficientOCRQuality

Claims (14)

1. A process for preparing merca tans which comprises reacting hydrogen sulfide with a) an a-olefin wherein said a-olefin is selected from the group consisting of ethylene, propylene, 1-butene, isobutene, 1-pentene, 1-hexene, 1-oetene, 1-nonene, styrene, 1-dadecene, 1-decene, 1-tridecene, l-undecene , 1-heptadecene, 2-meth l-hexene-1, 3-methyl-2-eth l-l-pentene, 3,3-dimethyl-l-heptene, 4-methyl-- 2-propyl-l-pentene, vinylcyclohexane, 3-phenyl-1-pentene, 1,3-butadiene, 1,3-pentadiene, 1,5-nexadiene, 1,7-octadiene, » &iethyl-l,5-hexadiene, 3-^A«*«-4-fe«x«a«, b) the substituted derivatives of said a-olefin, wherein the substituents are selected from the group consisting of cyano, nitro, chloro, carboxyl, ca on 1, tertiary amines, halogens, sulfoxides, sulones, hydroxyl, ethers, thioethers, carboxylic esters, amides, trivalent phosphorus groups, and pentavalen phosphorus groups; or c) olefins having inert groups attached directly to the olefinic carbo atom selected from the group consisting of cyano, halogen,ethers, carboxyl and carboxlate; and d) an initiator consisting essentially of a trivalent organic phosphorus compound having the formula R" ( )b fi»(X) - P - (z) Η··· a c wherein X, T and Z are each chalcogen having an atomic - 9a - 34486/1 weight between.15 and 33» a, b and c are each equal to 0 or 1{ and R', R!* and K'*' are each, a hydrocarbon radical having from 1 to 20 carbon atoms; said trivalent phosphorus compound being present in an amount from about 0.005 to about 1 mole per mole of olefinic linkage, at a temperature in the range from about 5O°0 to about 200°C. L i n 34486/2

2. The process of Claim 1 wherein said trivalent phosphorus compound is present, in an amount from about 0.01 to about 0.5 mole per mole of oleflnic linkage.

3. The process of Claim 1 wherei the process is carried out in the presence of an inert diluent.

4. . The process of Claim 1 wherein said phosphorus compound is a phosphite.

5. The process of Claim 1, wherein said phosphorus compound is a phosphine .

6. The process of Claim 1 wherein said phosphorus compound is trimethyl phosphite.

7. The process of Claim 1 wherein said phosphorus compound is triethyl phosphite.

8. The process of Claim 1 wherein said phosphorus compound is triphenyl phosphite.

9. The process of Claim 1 wherein said phosphorus compound is tributyl phosphite.

10. The process of Claim 1 wherein said phosphorus compound is tributylphosphine . ^

11. The process of Claim 1 wherein said phosphorus compound is trimethyl phosphine.

12. The process of Claim 1 wherein said phosphorus compound is triphenyl phosphine .

13. The process of Claim 1 wherein the olefin is ethylene .

14. The process of Claim 1 wherein the olefin, a propylene . For the Applicants DR. REINHOLD CQHN AND PARTNERS