1471898 Tricyclic sulphoximides WARNERLAMBERT CO 2 Oct 1974 [8 April 1974] 42770/74 Heading C2C Novel tricyclic sulphoximides of the general formula wherein X is a valency bond, an oxygen or sulphur atom, an optionally substituted imino group, a carbonyl group or a C 1-6  alkylene group, one cyclic carbon atom of which may be replaced by an oxygen or sulphur atom, a carbonyl group or an optionally substituted imino group and R is an optionally N-substituted aminoalkyl or aminoalkyl carbonyl group or a C 1-4  alkoxy-carbonyl group or an aminocarbonyl or aminothiocarbonyl group of formula -CX<SP>1</SP>NR 4 R 5 , in which X<SP>1</SP> is O or S and each of R 4  and R 5  is H or a C 1-6  saturated or unsaturated aliphatic hydrocarbon group or a C 2-4  alkanoyl or organosulphonyl group and pharmacologically compatible acid addition salts thereof (when a free basic amino group is present) are prepared by reacting the corresponding compound in which R is a hydrogen atom or an alkali or alkaline earth metal salt thereof with (a) an aminoalkyl halide of the general formula Hal(CH 2 ) m NR 1 R 2  to give a product in which R is an amino alkyl group (R 1  and R2 are each a C 1-7  aliphatic hydrocarbon group or together form a C 4-6  alkylene chain and m is 1-4); (b) a reactive derivative of an acid of the general formula HOOC(CH 2 ) n NR 1 R 2  to give a product in which R is an aminoalkylcarbonyl group (and n is 1-3); (c) a haloformic acid of the general formula halogen-COOR 3  to give a product in which R is an alkoxycarbonyl group (R 3  is a C 1-4  alkyl group); (d) an isocyanate or isothiocyanate of the general formula X<SP>1</SP>CNR 4  to give a product in which R is an aminocarbonyl or aminothiocarbonyl group as defined above, provided that R 4  is a hydrogen atom: or (e) a reactive derivative of a carbamic or thiocarbamic acid of the general formula to give a product in which R is an aminocarbonyl or aminothiocarbonyl group as defined above; followed optionally by salification of the product. Sulphoximides of the first general formula above wherein R is a hydrogen atom are prepared (i) by oxidizing sulphimide of the general formula or a salt thereof or (ii) by reacting a sulphoxide of the general formula  with a benzenesulphonyl azide of the general formula Ar-SO 2 -N 3 , wherein Ar is an optionally substituted phenyl group, in the presence of copper powder and methanol, or with O- mesitylene - sulphonyl - hydroxylamine, and hydrolysing the resulting N-arylsulphonyl-sulphoximide when the azide is used or converting the resulting mesitylenesulphonate salt to the free base when O-mesitylenesulphonylhydroxylamine is used. The sulphimides used in (i) above are prepared by reacting a sulphide of the general formula with O-mesitylenesulphonyl-hydroxylamine and converting the resulting mesitylenesulphonate salt to the free base. Phenothiazine-S-oximide is prepared by heating 10 - acetylphenothiazine - S - oximide with ethanolic KOH. N - chloroacetyl - phenoxathiine - S - oximide and 10 - methyl - phenothiazine - N - (3 - chloropropionyl) - S - oximide are prepared by reacting phenoxathiine-S-oximide or 10-methylphenothiazine-S-oximide, respectively, with the appropriate acyl chloride. Pharmaceutical compositions having antihistaminic, antitussive, antiphlogistic, sedative and diuretic activity comprise, as active ingredient, at least one novel tricyclic sulphoximide of the first general formula above or pharmacologically acceptable salt thereof, in admixture with a solid or liquid pharmaceutical diluent or carrier.