Patent GB-476570-A (GB)
Title: Manufacture of thiazolidine derivatives
IPC: C07D277/04
Filed: 1936-06-08
Abstract: Thiazolidine derivatives, which are probably O-ethers of mercaptohydroxythiazolidines, of the general formula <FORM:0476570/IV/1> where R is an organic radicle, R1 is hydrogen or an organic radicle, and R2 and R3 are hydrogen or substituents, are manufactured by reacting a xanthate with an ethylene imine or a salt thereof, or, in the absence of excess of alkali, with material from which an ethylene imine may be formed, e.g. a halogenalkylamine or an aminoalkylol sulphuric ester or a salt of one of these.  The reaction is preferably effected between equimolecular proportions of the xanthate, the ethylene imine, which may be in the form of a crude solution of technical purity, and an acid, or between one molecular proportion each of xanthate and halogenalkylamine or aminoalkylol sulphuric ester with the addition of one or two molecular proportions respectively of caustic soda.  In examples: (1) a solution of sodium methyl xanthate in methanol is mixed with a solution of ethyleneimine in aqueous acetic acid, producing 2 - mercapto - 2 - methoxythiazolidine, which may be converted, by boiling in alkaline solution, into 2-mercaptothiazoline; (2) a methanol solution of methyl xanthate is added to a mixture of N-methylethyleneimine, water and sulphuric acid, yielding N - methyl - 2-mercapto - 2 - methoxythiazolidine; (3) the sodium salt of octadecyl xanthate is reacted with ethyleneimine acetate in aqueous solution; (4) bornyl xanthate is reacted in aqueous solution with ethyleneimine sulphate; (5) unripened cellulose xanthate solution is diluted with water and neutralized to phenolphthalein by means of acetic acid, and there is added an aqueous solution of ethyleneimine acetate to produce 2-mercapto-2-hydroxythiazolidine-O-cellulose ether; (6) potato starch is dissolved in dilute caustic soda and kneaded with carbon disulphide, the product is neutralized by passing carbon dioxide, and a solution of ethyleneimine in aqueous acetic acid is added; (7) polyvinyl alcohol is made into a paste with caustic soda solution and shaken with carbon disulphide, the product is neutralized with dilute acetic acid, and a solution of ethyleneimine in aqueous acetic acid is added; (8) a solution of bromethylamine hydrobromide in caustic soda solution is warmed with a methanol solution of sodium methyl xanthate; (9) chlorethylamine hydrochloride is similarly treated; (10) N-ethylchlorethylamine hydrochloride is reacted similarly with an ethanol solution of potassium ethyl xanthate to produce ethyl mercaptoethoxythiazolidine; (11) potato starch is reacted with carbon disulphide as in (6), the product is diluted with water and neutralized with dilute acetic acid, and an aqueous solution of bromethylamine hydrobromide and caustic soda is added; (12) a methanol solution of sodium methyl xanthate is added to a heated solution of aminoethanol sulphuric ester in aqueous caustic soda. The Specification as open to inspection under Sect. 91 comprises the reaction of one equivalent of a xanthate with two or more equivalents of a cyclic imine or a salt thereof or with material from which two or more equivalents of a cyclic imine or a salt thereof can be formed.  Alternatively, the products obtained from one equivalent of each of the reactants are treated with one or more equivalents of a cyclic imine or a salt thereof or with material from which one or more equivalents of a cyclic imine or a salt thereof may be formed. In both cases, S-aminoalkyl ethers of the mercaptohydroxythiazolidine-O-ethers are probably formed. Additional examples describe the treatment of the product of (1) above with (a) bromethylamine hydrobromide in the presence of caustic soda, (b) chlorethylamine hydrochloride in the absence of or in the presence of various amounts of caustic soda, (c) diethylchlorethylamine hydrochloride in the presence of caustic soda, (d) ethyleneimine, and (e) methylethyleneimine acetate, and of the corresponding ethyl ether with methylchlorethylamine hydrochloride and caustic soda; and also the interaction in other than equivalent proportions of: (a) starch xanthate and ethyleneimine; (b) methyl xanthate and bromethylamine hydrobromide; (c) methyl xanthate and chlorethylamine hydrochloride; (d) ethyl xanthate and a mixture of ethyleneimine and diethylbromethylamine hydrobromide; (e) methyl xanthate and both bromethylamine hydrobromide and methylethyleneimine; (f) methyl xanthate and a mixture of ethyleneimine and methylethyleneimine; (g) methyl xanthate and ethyleneimine with or without acetic acid.  The following additional starting materials are specified: cyclic imines: 2-chlorethyleneimine, 2 : 3-dibromethyleneimine, ethyleneimine - 2 - carboxylic acid, ethyleneiminesulphonic acid, 2 : 3-diacetylethyleneimine, 2-octadecylethyleneimine, N - cyclohexanolethyleneimine, 2-phenylethyleneimine, N-propyl-2-vinylethyleneimine and trimethyleneimine; halogenalkylamines: all 1 : 2- or 1 : 3-halogenalkylamines and their substitution products, e.g. N-methylbromethylamine, 1 : 2-, 2 : 1- and 1 : 3-chloropropylamine, 2 : 3-bromobutylamine, N-butylchlorethylamine, dichlorodiethylamine, N-vinyl-2 - octadecylchlorethylamine, triiodotriethylamine and 4-phenyl-3-chloro-1-aminobutane; xanthates: butyl, oleyl and benzyl xanthate and xanthates of sugars, and metal compounds, e.g. sodium, barium and copper derivatives, thereof.  This subject-matter does not appear in the Specification as accepted.