Patent GB-783546-A (GB)
Title: Bis-mercaptomethyl aromatic compounds, their preparation and use
Filed: 1954-12-14
Abstract: Bis-mercaptomethyl compounds of formula HSCH2.Ar.CH2SH (see Group IV (b)), wherein Ar is a phenylene radical which may contain 1-4 methyl groups, may be condensed with bifunctional reagents to give resins. Compounds wherein the mercaptomethyl groups are in the para positions are preferred and give linear fibre-forming resins.  Specified bifunctional reagents are diacids, diacid chlorides, diolefins, dialdehydes, acrylonitrile and vinyl trichlorsilane.  The fibres may be cold-drawn to produce colourless filaments.  Mixtures of two or more mercaptans and/or of bifunctional reagents, such as acid chlorides (e.g. adipyl+ sebacyl or terphthalyl chlorides), may be used to modify the properties of the resin.  In examples: (1) bis-mercaptomethyl-2 : 3 : 5 : 6-tetramethyl-benzene was condensed with sebacyl chloride in the presence of nitrogen, the polyester product extruded and the resultant thread cold-drawn to give fibres; (2) as in (1) but using adipyl chloride or a mixture of adipyl and sebacyl chlorides; (3) as in (1) but condensing bis-mercaptomethyl-benzene with adipyl chloride.ALSO:Compounds of formula HSCH2.Ar.CH2SH are prepared from a starting material having the formula ZCH2.Ar.CH2Z, wherein Z is chlorine, bromine or iodine and Ar is a phenylene radical which may be substituted by 1-4 methyl groups, by preparing an intermediate by reacting 1 mol. of the starting material with 2 mols. of a compound having the formula <FORM:0783546/IV (a)/1> wherein Q is an amino radical NR2IV or a radical ORV and Y is an amino radical NR2IV or a thiol salt radical SM, RIV being hydrogen or an alkyl or aromatic radical containing 1-8 carbon atoms, RV being an alkyl or aromatic radical containing 1-8 carbon atoms and M being sodium, potassium or an ammonium radical and degrading the intermediate to the bismercaptan by hydrolysis with aqueous alkali when the intermediate is a thiouronium compound or by treatment with ammonia when the intermediate is a xanthate or a thiocarbamate or dithiocarbamate.  The preferred compounds are those wherein the mercapto-methyl groups are in the para-positions and such compounds may be condensed with bifunctional reagents to give linear polymers (see Group IV (a)).  Specified bis-halomethyl compounds are bis - chloromethyl - 2 : 3 : 5 : 6 - tetramethylbenzene, para - bis - chloromethyl - benzene, 2 : 5 - bis - chloromethyl - 1 : 4 - dimethylbenzene and bis-halomethylated mixed xylenes.  Specified compounds of formula <FORM:0783546/IV (a)/2> are thiourea, sodium dithiocarbamate, potassium ethyl xanthate, tetramethyl thiourea, ammonium di-isopropyl dithiocarbamate, phenyl diphenylthiocarbamate and sodium octyl xanthate.  In examples: (1) bis-chloromethyldurene (i.e. bis-chloromethyl-2 : 3 : 5 : 6-tetramethylbenzene) was reacted with thiourea to give a thiouronium compound which was hydrolysed to bis-mercaptomethyl-durene with an aqueous alcohol solution of potassium hydroxide; (2) bis-chloromethyl-durene was reacted with potassium ethyl xanthate to give bis-ethylxanthomethyl-durene which was converted to bis-mercaptomethyl-durene by treatment with alcoholic ammonia.