GB631007A - Production of monocyclic aromatic tricarbonimides and related compounds - Google Patents

Abstract

Monocyclic aromatic tricarbonimides (isocyanates) are prepared by reacting one mole. of an aromatic triamine of the formula <FORM:0631007/IV (b)/1> where R is hydrogen, an alkyl, alkoxy or aryloxy group dissolved in an organic solvent with at least 1.5 moles. of phosgene dissolved in an organic solvent, heating the resulting suspension to a temperature not lower than 90 DEG C. and passing in phosgene and removing liberated hydrogen chloride, the solvent used being inert to the starting materials and also to hydrogen chloride and the organic reaction products. The solvent is preferably one having a boiling point below 160 DEG C. and may suitably be a hydrocarbon, halogenated hydrocarbon or an ether, e.g. toluene, xylene, dioxane, monochlorobenzene, orthochlorotoluene or mixtures of these with benzene or ethylene dichloride. The suspension is preferably maintained at 100-130 DEG C. while the phosgene is passed on and if desired, the phosgene may be admixed with an inert diluent gas to assist the removal of the hydrogen chloride. Aromatic chloro carbonimides are formed at intermediate stages of the reaction. In examples (1) 2 : 4 : 6-triaminotoluene in ethylene dichloride is added to a solution of phosgene in monochlorobenzene and a stream of phosgene is passed in to give toluene 2 : 4 : 6-tricarbonimide; (2) 2 : 4 : 6-triaminotoluene in monochlorobenzene is added to phosgene in monochlorobenzene and phosgene is passed in to give toluene-2 : 4 : 6-tricarbonimide; (3) 1 : 3 : 5-triaminobenzene is reacted with phosgene as in (1) to give benzene tricarbonimide and (4) 2 : 4 : 6-triaminophenetole is reacted with phosgene in xylene and further phosgene is passed in to give ethoxybenzene-2 : 4 : 6-tricarbonimide. Aromatic triurethanes are prepared from the tricarbonimides in the examples by treatment with alcohols giving toluene-2 : 4 : 6-triurethane benzene-1 : 3 : 5-triurethane and ethoxybenzene-2 : 4 : 6-triurethane. Aromatic tricarbamides are prepared from the tricarbonimides of the examples by treatment with dry ammonia in ether giving toluene-2 : 4 : 6-tricarbamide; benzene-1 : 3 : 5-tricarbamide, and ethoxybenzene-2 : 4 : 6-triurethane. Specification 625,350 is referred to.