An alkyl mercaptan is prepared by reacting an aliphatic alcohol with hydrogen sulfide in the presence of a heterogeneous catalyst at varying temperatures.

The present invention relates to a catalyst which comprises a support material and an oxidic composition containing at least one alkali metal and tungsten, a process for producing such catalysts and also a process for preparing alkyl mercaptans by reaction of alkanols with hydrogen sulphide in the presence of such a catalyst.

The present invention relates to a catalyst which comprises a support material and an oxidic composition containing at least one alkali metal and tungsten, a process for producing such catalysts and also a process for preparing alkyl mercaptans by reaction of alkanols with hydrogen sulphide in the presence of such a catalyst.

The present invention relates to a catalyst which comprises a support material and an oxidic composition containing at least one alkali metal and tungsten, a process for producing such catalysts and also a process for preparing alkyl mercaptans by reaction of alkanols with hydrogen sulphide in the presence of such a catalyst.

A catalyst may include a support and from 5 to 20 wt.-% of a promoter, based on the total weight of the catalyst, wherein the support may include titanium dioxide, zirconium dioxide, and/or a mixture thereof, and the promoter may be an alkali metal oxide. Processes for preparing such catalysts may include impregnating a support of titanium dioxide and/or zirconium dioxide with an aqueous solution including a preferably soluble alkali compound and calcining. Alkyl mercaptans may be prepared in the presence of such catalysts or catalysts obtained by such processes.

A catalyst may include a support and from 5 to 20 wt.-% of a promoter, based on the total weight of the catalyst, wherein the support may include titanium dioxide, zirconium dioxide, and/or a mixture thereof, and the promoter may be an alkali metal oxide. Processes for preparing such catalysts may include impregnating a support of titanium dioxide and/or zirconium dioxide with an aqueous solution including a preferably soluble alkali compound and calcining. Alkyl mercaptans may be prepared in the presence of such catalysts or catalysts obtained by such processes.

A method for preparing a compound of formula RSH where R represents an alkyl group, by gas-phase catalytic reaction of hydrogen sulfide with a compound of formula ROH, in the presence of a solid catalyst, according to which method the reaction is performed in the presence of a catalyst which includes one or several pure or mixed rare-earth oxide(s), one or several pure or mixed rare-earth sulfide(s), or one or several pure or mixed rare-earth oxysulfide(s). When the rare earth is lanthanum, the catalyst is a mixed oxide of lanthanum and of at least one metal selected from rare earths or not and when the rare earth is cerium, the catalyst is supported on an alumina.

A method for preparing a compound of formula RSH where R represents an alkyl group, by gas-phase catalytic reaction of hydrogen sulfide with a compound of formula ROH, in the presence of a solid catalyst, according to which method the reaction is performed in the presence of a catalyst which includes one or several pure or mixed rare-earth oxide(s), one or several pure or mixed rare-earth sulfide(s), or one or several pure or mixed rare-earth oxysulfide(s). When the rare earth is lanthanum, the catalyst is a mixed oxide of lanthanum and of at least one metal selected from rare earths or not and when the rare earth is cerium, the catalyst is supported on an alumina.

The present invention relates to a process for synthesizing functionalized mercaptans essentially in the absence of oxygen, and also to a composition making it possible in particular to implement this process. Said functionalized mercaptans are of the following formula (I):

##STR00001##

in which, R.sub.1 and R.sub.7, which are identical or different, are a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; X is chosen from -C(=O)-, -CH.sub.2- or -CN; R.sub.2 is: (i) either absent when X represents -CN, (ii) or a hydrogen atom, (iii) or -OR.sub.3, R.sub.3 being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms, (iv) or -NR.sub.4R.sub.5, R.sub.4 and R.sub.5, which are identical or different, being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; n is equal to 1 or 2; and * represents an asymmetric carbon.

The present invention relates to a process for synthesizing functionalized mercaptans essentially in the absence of oxygen, and also to a composition making it possible in particular to implement this process. Said functionalized mercaptans are of the following formula (I):

##STR00001##

in which, R.sub.1 and R.sub.7, which are identical or different, are a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; X is chosen from -C(=O)-, -CH.sub.2- or -CN; R.sub.2 is: (i) either absent when X represents -CN, (ii) or a hydrogen atom, (iii) or -OR.sub.3, R.sub.3 being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms, (iv) or -NR.sub.4R.sub.5, R.sub.4 and R.sub.5, which are identical or different, being a hydrogen atom or an aromatic or nonaromatic, linear, branched or cyclic, saturated or unsaturated, hydrocarbon chain of 1 to 20 carbon atoms which may comprise one or more heteroatoms; n is equal to 1 or 2; and * represents an asymmetric carbon.