Patent GB-769440-A (GB)
Title: New phenthiazine derivatives and processes for their preparation
Inventor: JACOB ROBERT MICHEL
IPC: C07D279/18
Filed: 1954-01-12
Abstract: The invention comprises compounds containing a cation represented by the general formula: <FORM:0769440/IV(b)/1> or by the general formula: <FORM:0769440/IV(b)/2> wherein A represents a straight or branched chain divalent aliphatic hydrocarbon group comprising 2 or 3 carbon atoms, R represents methyl or ethyl, R1 represents a hydrogen atom or an alkyl group containing 1 to 4 carbon atoms or a benzyl group (or aryl in formula I), and Y represents a hydrogen or halogen atom or a methyl, methoxy or phenoxy group in the 1- or 3-position and the phenthiazine ring may be further substituted, and X (in formula I) represents the acid residue of a reactive ester.  The invention also comprises a compound of formula I in admixture with a trans compound of formula II.  Such compounds are obtained, with or without a proportion of compounds containing cations represents by the general formula: <FORM:0769440/IV(b)/3> by condensing a di(b -substituted-ethyl)amine of the formula (XCH2CH2)2N-R1 with a phenthiazine derivative of the formula <FORM:0769440/IV(b)/4> at a temperature between 25 DEG  and 110 DEG  C. in a polar solvent medium using, when the temperature is from 50 DEG  to 110 DEG  C., less than two mols. of the phenthiazine derivative per mol. of the substituted amine, or at a temperature between 110 DEG  and 250 DEG  C. in the presence or absence of a solvent.  (Some of the compounds containing the cation of formula III are the subject of Specification 756,937.) Reaction between about 25 DEG  and 50 DEG  C. in a polar solvent yields almost exclusively compounds with a cation of formula I, preferably reactants in equimolecular amounts being used.  At 50 DEG to 110 DEG  C. in a polar solvent, preferably boiling ethanol, equimolecular proportions of reactants yield a mixture of compounds having cations of types II and III.  With two or more molecular proportions of phenthiazine derivative per mol. of amine, the product contains almost exclusively cations of formula III, while with 1 to 2 molecular proportions, a product containing all three cations is obtained.  At 110 DEG  to 250 DEG  C., preferably 120 DEG  to 140 DEG C., a mixture of products containing the cations of formulae I and II, with or without a proportion of formula III is obtained.  A diluent such as toluene or a polar solvent such as mesityl oxide, benzonitrile or dimethylformamide may be present. A reaction mixture such as obtained at this temperature is obtained by heating the reaction products obtained under the other sets of reaction conditions.  The products can be separated by chromatography, preferably on alumina or by fractional precipitation.  Products of type II (trans) can be separated from those of types I and III (cis) by fractional precipitation of the sulphates or salting out the chlorides.  Products of types II and III (cis form) as chlorides may be separated utilizing the different solubility in alcohol.  The products may be isolated by precipitation as their methylene-bis-b -hydroxynaphthoic acid salts.  In examples: (1) 3-chloro - 10 - (21 - dimethylaminoethyl) phenthiazine and N : N-di-(2-chloroethyl) methylamine (in about equimolecular amounts) are heated together at 125-135 DEG  C. to give a product containing 1 - (31 - chlorophenthiazinyl - 101)-3 : 3 : 6 - trimethyl - 6 - azanium - 8 - chlorooctane, 1 : 4 - dimethyl - 1 : 4 - di - 51 - (311 -chloro - 1011 - phenthiazinyl) - 31 : 31 - dimethyl -31 - azanium - 11 - pentyl) - piperazinium tetrachloride and 1 : 11 - di - b 1 - chlorophenthiazinyl -101) - 3 : 3 : 6 : 9 : 9 - pentamethyl - 6 - aza - 3 : 9 -diazaniumundecane dichloride; (2) a mixture containing the same products is obtained using the reactants in a mol. ratio of about 4 : 1; (3) the same reactants in equimolecular proportions are employed, toluene being present in the mixture.  From the product there is obtained (via the sulphate obtained by precipitation with sulphuric acid) 1 : 4-dimethyl-1 : 4-di[51 - (311 - chloro - 1011 - phenthiazinyl) - 31 : 31-dimethyl - 31 - azanium - 11 - pentyl] piperazinium chloride (assumed to be in the trans form) from which the picrate and iodide are prepared; (4) mesityl oxide is present as solvent; (5) reaction is effected in the presence of dimethylformamide and the mixed product is precipitated with sodium methylene-bis-b -hydroxynaphthoate; (6) from the same reactants in equimolecular amount in the presence of ethanol at room temperature there is obtained by extraction with ether and recrystallization 3 : 5 : 6 - trimethyl - 8 - chloro - 6 - aza - 3-azanium (31-chloro-101-phenthiazinyl) octane. Further examples describe the preparation by methods such as those above of (7) 1 : 4-dimethyl - 1 : 4 - di[51 - (311 - chloro - 1011 - phenthiazinyl) - 31 : 310 - dimethyl - 31 - azanium - 11 -pentyl]-piperazinium tetrachloride, assumed to be of cis form); (8) 1 : 4-dimethyl-1 : 4-di[51-(1011 - phenthiazinyl) - 3 : 31 - dimethyl - 31-azanium - 11 - pentyl]piperazinium tetrachloride; (9) the corresponding 3-methylphenthiazinyl derivative; (10) the same product as in (4) by a process in which a reaction product obtained at room temperature is further heated at 130 DEG  in benzonitrile; (11) trans 1 : 4 - dimethyl - 1 : 4 - di[61 - (311 - chloro-1011 - phenthiazinyl) - 31 : 31 - dimethyl - 31-azanium - 11 - hexyl]piperazinium tetraiodide; (12) trans - 1 : 4 - dimethyl - 1 : 4 - di[51 - (311 -phenoxy - 1011 - phenthiazinyl) - 31 : 31 - dimethyl - 31 - azanium - 11 - pentyl]piperazinium tetrachloride; (13) trans-1 : 4-dimethyl-1 : 4-di [51 - (111 - chloro - 1011 - phenthiazinyl) - 3 : 31 -dimethyl - 31 - azanium - 11 - pentyl] piperazinium tetrachloride. Analagously can be prepared the chlorides of 3,3,6-trimethyl-8-chloro-6 - aza - 3 - azanium - 1 - (31 - methoxy - 101 -phenthiazinyl) octane, 3,3 - dimethyl - 6-benzyl - 8 - chloro - 6 - aza - 3 - azanium - 1 - (31 -methyl - 101 - phenthiazinyl) octane and 3,3-dimethyl - 6 - formyl - 8 - chloro - 6 - aza - 3-azanium - 1 - (31 - chloro - 101 - phenthiazinyl) octane.ALSO:Mixture of compounds containing a cation represented by the formulae <FORM:0769440/VI/1> and the trans form of <FORM:0769440/VI/2> respectively, wherein A represents a saturated straight or branched chain divalent aliphatic hydrocarbon group comprising 2 or 3 carbon atoms, the substituents R represent methyl or ethyl radicals, R1 represents a hydrogen atom or an alkyl group comprising 1 to 4 carbon atoms or a benzyl group or (in the first formula only) an acyl group, Y represents a hydrogen or halogen atom or a methyl methoxy or phenoxy group in the 1- or 3-position and the phenthiazine ring may be further substituted and X represents the acid residue of a reactive ester, have pharmacological (including spasmolytic and local anaesthetic) properties.  Compounds of the first formula have a synergistic effect with respect to compounds of the second formula.  The preparation of compounds containing such ions is described (see Group IV(b)).