Abstract: Hydrogen chloride gas obtained as a by-product in the production of chloroacetic acid by subjecting acetic acid to a catalytic chlorination reaction with chlorine gas in the presence of acetic anhydride and/or acetyl chloride is purified. The prepurified by-product still contains 0.1-3 vol % acetyl chloride and up to 0.1 vol % chloroacetyl chloride. For purification, the hydrogen chloride gas is passed through two zones series-connected together and scrubbed in countercurrent fashion. More particularly, it is scrubbed in the first zone with concentrated hydrochloric acid and in the second zone with concentrated sulfuric acid.

Abstract: Continuous production of 2,5-dioxo-1-oxa-2-phospholanes of the general formula ##STR1## from a beta-halogenoformyl-ethyl phosphinic acid halide of the general formulaR.sup.1 XP(O)--CHR.sup.2 --CHR.sup.3 --CO--Xin which formula R.sup.1 stands for an alkyl radical having 1, 2, 3 or 4 carbon atoms, or a phenyl radical, R.sup.2 and R.sup.3 each stands for hydrogen or CH.sub.3, and X stands for chlorine or bromine, by reacting the said acid halide with acetic anhydride. The phospho lanes are produced by introducing, into a heatable circulation reactor, an initial quantity of the desired 2,5-dioxo-1-oxa-2-phospholane and circulating it therein at a temperature of 110.degree. to 190.degree. C; separately preheating the respective beta-halogenoformyl-ethyl phosphonic acid halide and acetic anhydride starting materials to a temperature of 60.degree. to 160.degree.

Abstract: Preparation of 2,5-dioxo-1,2-oxa-phospholanes of the formula (I) ##STR1## wherein R.sup.1 represents an optionally substituted alkyl having up to 18 carbon atoms, a cycloalkyl radical having up to 8 carbon atoms, an alkylene radical having up to 8 carbon atoms, an aryl radical having up to 14 carbon atoms which may be substituted by lower alkyl groups, lower alkoxy groups, halogen or by amino groups alkylated or dialkylated by lower alkyl groups, or an aralkyl radical having up to 15 carbon atoms which may be substituted in an analogous manner as the aryl radical, R.sup.2 represents a lower alkyl radical or hydrogen and R.sup.3 represents an alkyl radical having up to 6 carbon atoms, a phenyl radical which may be substituted by halogen or by lower alkyl groups, a benzyl radical or hydrogen, by reacting 2-halogenoformylethylphosphonic acid halides of the formula (II) ##STR2## wherein R.sup.1, R.sup.2 and R.sup.

Abstract: In an improvement of the process of U.S. patent No. 3,941,752, according to which flame retarding linear polyesters are manufactured by reaction of dicarboxylic acids capable of forming high molecular weight linear polyesters or the esters thereof with lower aliphatic alcohols, with diols, and phosphorous compounds of the formula ##STR1## or the esters thereof with lower aliphatic alcohols or also the cyclic anhydrides thereof, the cyclic anhydrides are used after having been dissolved previously at elevated temperature in a diol suitable for the polyester manufacture, preferably in the diol used as main component. The symbols of the formula have the following meanings: R = saturated open-chain or cyclic alkylene, arylene or aralkylene, R.sub.1 = alkyl having up to 6 carbon atoms, aryl or aralkyl; R as well as R.sub.1 optionally containing 1 or more hetero atoms, preferably F, Cl, Br, O or S.

Abstract: Beta-halogenoformyl-ethyl phosphinic acid halides of the general formula:R.sup.1 XP(O)--CHR.sup.2 --CHR.sup.3 --CO--X,in which R.sup.1 stands for an alkyl radical having 1, 2, 3 or 4 carbon atoms or a phenyl radical, R.sup.2 and R.sup.3 each stand for hydrogen or CH.sub.3, and X stands for chlorine or bromine, are produced by reacting an alkyldihalogenophosphine having 1, 2, 3 or 4 carbon atoms in its alkyl radical, or a phenyldihalogenophosphine, with acrylic acid, methacrylic acid or crotonic acid. To this end, a quantity of the desired beta-halogenoformyl-ethyl phosphinic acid halide is introduced into a reaction zone and circulated in the form of a melt at 50.degree. to 120.degree. C and at a flow rate of 0.1 to 3 m/s.

Abstract: 2,5 DIOXO-1-OXA-2-PHOSPHOLANES OF THE GENERAL FORMULA: ##STR1## in which R.sup.1 stands for an alkyl radical having from 1 to 4 carbon atoms, or a phenyl radical, and R.sup.2 and R.sup.3 each stand for hydrogen or CH.sub.3, are distillatively purified. To this end the respective crude compound is preheated to 120.degree. to 160.degree. C and fed to the head of a distilling column provided with a plurality of individually heatable trays maintained at temperatures increasing from the upper-most tray to the lowermost, the uppermost tray in the column being maintained at 120.degree. to 160.degree. C and the lowermost tray being maintained at 160.degree. to 200.degree. C, the pressure at the head of the column being 20 to 200 mm Hg, preferably 50 to 120 mm Hg; an inert gas preheated to 160.degree. to 200.degree.