Abstract: A process for producing tetrabromobisphenol A of high quality, which comprises brominating bisphenol A with bromine, wherein a solvent mixture comprising a hydrohalogenic acid and an alcohol, is used as the solvent for reaction. Also disclosed is a process for producing tetrabromobisphenol A of high quality, which comprises brominating bisphenol A with bromine in an alcohol, wherein the reaction temperature is set at a level of from -10.degree. to +20.degree. C., and water is added in an aging step.

Abstract: A process for producing tetrabromobisphenol A, which comprises brominating bisphenol A in methanol, wherein the substrate concentration of bisphenol A to methanol is at most 20 wt/vol %.

Abstract: A radiation-resistant high molecular composition is disclosed, charqacterized in that, to the high molecular polymer, a halogenated acenaphtylene and/or condensates thereof represented by a following general formula [I] ##STR1## (wherein, X indicates a chlorine or bromine atom, a indicates 0 to 2, b indicates 1 to 6 and n indicates an integer not less than 1) and a diphenyl ether derivative represented by a following general formula [II] ##STR2## (wherein, R.sub.1 and R.sub.2 indicate any ones of hydrogen atom, alkyl, alkoxy, phenyl phenoxy, diphenyloxy and terphenyloxy group) and/or basic lead compound are formulated.

Abstract: A process for producing tetrabromobisphenol A, which comprises brominating bisphenol A in methanol, wherein the substrate concentration of bisphenol A to methanol is at most 20 wt/vol %.

Abstract: A 4,4'-bis(phthalimido)diphenyl sulfone compound having the formula: ##STR1## wherein X is a halogen atom, k=0 to 4, l=0 to 4, m=0 to 4 and n=0 to 4, provided k+l+m+n>1.

Abstract: A method for producing 4,4'-dibromobiphenyl, which comprises reacting biphenyl and from 2 to 3 mol times, relative to biphenyl, of bromine in a halogenated hydrocarbon solvent in the presence of a catalyst which is a simple substance of an element selected from the group consisting of antimony, titanium, tin and zinc, or a compound of the element.

Abstract: A radiation-resistant high molecular composition is disclosed, characterized in that, to the high molecular polymer, a halogenated acenaphtylene and/or condensates thereof represented by a following general formula [I] ##STR1## (wherein, X indicates a chlorine or bromine atom, a indicates 0 to 2, b indicates 1 to 6 and n indicates an integer not less than 1) and a diphenyl ether derivative represented by a following general formula [II] ##STR2## (wherein, R.sub.1 and R.sub.2 indicate any ones of hydrogen atom, alkyl, alkoxy, phenyl phenoxy, diphenyloxy and terphenyloxy group) and/or basic lead compound are formulated.

Abstract: A process for producing brominated acenaphthylene condensates of the formula: ##STR1## wherein x is 1 or 2, y is an integer from 1 to 6 and n is 1 or more, from elementary units of the following formulas: ##STR2## wherein y is as defined above, comprising, (A) brominating the side chain of the acenaphthene with 0.2 to 2.0 times as many moles of bromine as acenaphthene, said bromination initiated by ultraviolet radiation or by a radical initiator in a halogenated hydrocarbon solvent, (B) adding a Lewis acid catalyst to the reaction solution of step (A) to promote the condensation of the brominated acenaphthene product of step (A), (C) adding to the reaction solution of step (B) an equimolar or more amount of bromine relative to the amount of acenaphthene starting material, to further brominate and condense the brominated acenaphthene and/or brominated acenaphthene condensates; and (D) dehydrobrominating the brominated acenaphthene condensates.

Abstract: A method for preparing Con-BAN, in which Con-AN is reacted with bromine in the presence of an iron Lewis acid catalyst and in which the solution of Con-AN and bromine are supplied simultaneously at a given rate into a reactor already containing a halogenated hydrocarbon and an iron catalyst.

Abstract: Process for producing condensed bromoacenaphthylene comprising:(A) a step of brominating and condensating acenaphthene with bromine in a halogenated hydrocarbon solvent in the presence of a Lewis acid catalyst;(B) a step of removing the Lewis acid catalyst and then continuing the bromination with bromine with an added radical initiator; and(C) a step of carrying out dehydrobromination reaction.In a modified process, the bromination is effected in a halogenated hydrocarbon solvent at a temperature not lower than 60.degree. C. using bromine at least 3 times as much in moles as acenaphthene in the presence of an iron catalyst.Further, the condensed bromoacenaphthylene is purified by bringing it into contact with an adsorbent in an organic solvent.

Abstract: The invention provides a novel and efficient method for the elimination of protecting groups, e.g. benzyloxycarbonyl group, from a protected amino acid, peptide or derivative thereof having at least one functional group protected by a protecting group, e.g. a lower alkyl ester of N-benzyloxycarbonyl-.alpha.-L-aspartyl-L-phenylalanine by catalytic hydrogen reduction to produce free amino acid, peptide or derivative thereof. In contrast to the conventional procedures in which the reaction is carried out in a solvent dissolving both the starting compound and the product compound or a solvent dissolving the starting compound but not dissolving the product compound, the inventive method utilizes a binary two-phase reaction medium composed of water and an organic solvent not freely miscible with water such as toluene.

Abstract: A side chain of m-phenoxytoluene is brominated with a polyhalogenated ethane having the formula ##STR1## wherein W and Z respectively represent Cl or Br and X and Y respectively represent Cl, Br or H, as a brominating agent in a liquid phase in the presence of an amorphous carbon.

Abstract: A method for purifying an .alpha.-L-aspartyl-L- phenylalanine lower alkyl ester containing impurities. The .alpha.-L-aspartyl-L-phenylalanine lower alkyl ester is brought into contact with a Cl-type anion exchange resin in an aqueous medium to have the impurities adsorbed by the anion exchange resin. The impurities contained in the .alpha.-L-aspartyl-L-phenylalanine lower ester, particularly diketopiperazine and .alpha.-L-aspartyl-L-phenylalanine are selectively and easily removed. The desired matter thus can be easily recovered and disposal of waste liquid, etc. can also be carried out without difficulty.