GB817932A - New compounds derived from tetrahydro-oxazine compounds and theophylline or halogen-theophyllines - Google Patents

Abstract

Water-soluble tetrahydro-1 : 4-oxazine derivatives are prepared by reacting a tetrahydro-1 : 4-oxazine of the formula <FORM:0817932/IV (b)/1> (wherein R1 is phenyl or substituted phenyl such as 4-hydroxy-, 3 : 4-dihydroxy- or o-chloro phenyl, R2 is an alkyl radical of at most 3 carbon atoms and R3 is hydrogen, an alkyl radical of at most 3 carbon atoms or hydroxyethyl) with theophylline or an 8-halogenotheophylline, preferably in molar proportions. The reactants may be heated alone to 128 DEG to 130 DEG C. or they may be refluxed in a solvent, e.g. an organic solvent such as methanol, or water, or they may be intimately ground together alone or in presence of a solvent, e.g. acetone. Alternatively, a salt of the tetrahydro-1 : 4-oxazine, e.g. its sulphate or hydrosulphate, is reacted with the theophylline compound in the presence of a quantity of an alkaline earth metal hydroxide equivalent to the quantity of sulphate present in a solvent, e.g. water or methanol, and the alkaline earth metal salt formed is removed. The product may be recovered from these processes by evaporation of the solvent where used or it may be isolated as an aqueous solution. Optically active tetrahydro-1 : 4-oxazines may be used in these processes. In examples: (1) 2 - phenyl - 3 - methyl - tetrahydro - 1 : 4 - oxazine and 8-chlorotheophylline are ground together to give a water-soluble product; (2) 2-(21 - chloro - phenyl) - 3 - methyl - tetrahydro - 1 : 4-oxazine and 8-chlorotheophylline are boiled together in methanol and the solution evaporated to give a solid product; (3) 2-(41-hydroxyphenyl) - 3 - methyl - tetrahydro - 1 : 4-oxazine hydrosulphate and theophylline in methanol are mixed with a concentrated baryta solution and boiled to give, on filtering off the barium sulphate, an aqueous solution of the required compound; and (4) 2-phenyl-3-methyl-4-hydroxyethyl - tetrahydro - 1 : 4 - oxazine and 8-chlorotheophylline are ground together in acetone to give a solid product.ALSO:Therapeutic compositions comprise aqueous solutions of compounds formed by the reaction of tetrahydro-1 : 4-oxazines of the formula <FORM:0817932/VI/1> (wherein R1 is phenyl or substituted phenyl such as 4-hydroxy-, 3 : 4-dihydroxy- or o-chloro-phenyl, R2 is an alkyl radical of at most 3 carbon atoms and R3 is hydrogen, an alkyl radical of at most 3 carbon atoms or hydroxyethyl) with theophylline or an 8-halogeno-theophylline. Examples are given.