Process for the preparation of Isoindoline

1,171,736. Isoindoline. ARZNEIMITTELWERK DRESDEN VEB. 27 Aug., 1968, No. 40843/68. Heading C2C. Isoindoline is produced by a process in which an o-halomethyl-benzyl hexamethylene tetraminium halide of general formula in which X is chlorine or bromine, is left to stand 1-3 days in the form of a solution in aqueous methanol, aqueous ethanol or aqueous isopropanol which contains by weight 24-33% of water and 6À5-20% of hydrochloric or hydrobromic acid or a slurry thereof in methanol, ethanol or isopropanol has hydrogen chloride or hydrogen bromide passed therethrough for 1À5 hours and the mixture is left to stand for 1 day; the reaction mixture obtained is then evaporated to dryness under reduced pressure thus producing an o-halomethyl benzylamine hydrohalide of the general formula which is subjected to ring closure by heating in water, methanol, ethanol, isopropanol, dioxan, benzene or toluene at 65-82‹ C. in the presence of an inorganic or organic base.