Patent GB-460889-A (GB)
Title: Manufacture of cyanic or thiocyanic anhydrides and condensation products thereof
Filed: 1935-07-30
Abstract: Compounds of the formul  <FORM:0460889/IV/1> and <FORM:0460889/IV/2> in which R represents an alkyl or aryl radicle and R<1> an alkyl radicle, are obtained when an alkyl or aryl or alkyl-aryl dithiocarbamic acid or a xanthic acid or a salt of one of the acids is treated at a low temperature with cyanogen chloride.  The compounds, which are somewhat unstable, can be reacted with mercaptans, phenols and primary or secondary amines, or with different dithiocarbamic or xanthic acids than those used in their preparation, to form unsymmetrical products with elimination of sulphocyanic acid.  Usually the second reactant is employed in the form of its alkali metal compound or an alkaline agent is added to bind the sulphocyanic acid.  The products, which have the formul <FORM:0460889/IV/3> and <FORM:0460889/IV/4> in which X represents the residue of a mercaptan, phenol, amine, dithiocarbamic or xanthic acid, are useful as vulcanization accelerators, anticryptogamic products and dyestuffs.  Examples describe the preparation of (CH3)2N.CS.S.CS.N(C2H5)2 and (CH3)2N.CS.NH.C6H4.OCH3 by passing cyanogen chloride at 0 DEG  C. into an aqueous solution of sodium dimethyldithiocarbamate, isolating the product, and condensing it in aqueous solution with sodium diethyldithiocarbamate or with p-anisidine whilst adding sodium carbonate to maintain the solution slightly alkaline.  The formul  of the products derived from the following components are listed: (1) (CH3)2 N.CS.SCN and sodium mercapto-benzothiazolate, diethyldithiocarbamate, methylxanthate, ethylxanthate, isopropylxanthate, butylxanthate, isoamylxanthate, phenolate, o-nitrophenolate, o-cresolate, p-cresolate and 2-nitro-4-methylphenolate; (2) (C2H5)2N.CS.SCN and sodium mercapto-benzothiazolate; (3) (CH3)2N.CS.SCN and aniline, p-toluidine, p-anisidine and monomethylaniline in presence of alkali; (4) (CH3)(C6H5)N.CS.SCN and sodium mercapto - benzothiazolate. U.S.A. Specifications 1,674,122 and 1,788,632 are referred to.  The Specification as open to inspection under Sect. 91 also describes the production of symmetrical products without the isolation of the intermediate product.  The cyanogen chloride is then introduced into the solution of the dithiocarbamate or xanthate at a temperature of 20--60 DEG  C.  Symmetrical products of the formula R.CS.S.CS.R are listed, in which R stands for OCH3, OC2H5, OC3H7, OC4H9, OC5H11, N(CH3)2 and N(CH3)(C6H5).  It also states that the intermediate may be prepared from any derivative of dithiocarbonic acid and using other cyanogen halides, and that it may be reacted with all compounds containing a mobile hydrogen atom.  The Specification also describes the interaction of cyanogen chloride in the cold with sodium mercapto-benzothiazolate to give thiocyano-benzothiazole, which may then be reacted with a xanthate as above with elimination of sodium sulphocyanate, or with sodium mercapto-benzothiazolate to form the disulphide with elimination of sodium cyanide.  Reference is also made to  <FORM:0460889/IV/5> This subject-matter does not appear in the Specification as accepted.