Bisphenol-A is prepared by reacting an excess of phenol with acetone in the presence of a modified sulfonic acid cationic exchange resin catalyst having a plurality of sulfonic acid sites of the general formula ##STR1## in which IER represents the ionic exchange resin backbone, each a and b is an integer from 0 to about 5, and each R is selected independently from H, OH, SH and alkyl groups. The catalyst exhibits high activity and selectivity at moderate reaction temperatures, low production of colored impurities, and high stability.

Process and alkylmercaptoamine catalyst for production of bisphenol-A

PURPOSE: To carry out purification by an extremely simple method, by removing impurities consisting essentially of an unreacted monomer contained in an aqueous solution of a cationic water-soluble polymer prepared by a solution polymerization method using an ion exchange membrane electrodialytic method. CONSTITUTION: An aqueous solution of a cationic a water-soluble polymer (e.g. polyallylamine, polydimethylaminoethylmethacrylamide or dimethyldiallylammonium chloride) obtained by solution polymerizing a cationic monomer is purified by subjecting the solution to ion exchange membrane electrodialysis to remove impurities consisting essentially of the unreacted monomer. Thereby the unreacted monomer can be removed to about 0.1W0.3% and safety is increased without evaporating toxic gases, since heat is applied to the monomer. COPYRIGHT: (C)1988,JPO&Japio

Method for purifying cationic water-soluble polymer

An aqueous organic solvent having al amino group is efficiently separated and recovered from ~ solution containing the aqueous organic solvent having al amino group at a high concentration and high purity suffi cient for re-use. Specifically, a solution containing al aqueous organic solvent having an amino group is intro duced into a dilution chamber (16) of an electric deionize lion apparatus (10A) which comprises an anode (11),cathode (12), and the dilution chamber (16) and a concert tration chamber (15) which are arranged between the an ode (11) and the cathode (12) and divided by ion-perme able separation membranes (13, 14). By applying a direct current voltage between the anode (11) and the cathode (12), the aqueous organic solvent having an amino grout contained in the solution that has been introduced into the dilution chamber (16) is caused to permeate through the separation membrane (14), thereby being separated ant recovered in the concentration chamber (15).

Apparatus and method for separating and recovering aqueous organic solvent having amino group

Molded particles of cysteamine hydrochloride obtained by preparing cysteamine hydrochloride powder having a water content of not more than 1% by weight and compression molding said cysteamine hydrochloride under a pressure of not less than 50 atmospheres, and granules of cysteamine hydrochloride obtained by cooling and solidifying a molten cysteamine hydrochloride, and manufacture thereof.

Method for production of granular cysteamine hydrochloride

PURPOSE:To utilize effectively a disk, and to shorten the access time of the time of recording and reproducing by repeating by a prescribed number of times of sectors respectively, a recording means for recording the information by a sector unit to a disk-shaped recording medium, and a checking means for executing an error check of the recorded information. CONSTITUTION:A data d1 is sent to a buffer memory BM1 from a host side by the first rotation of a disk, and by the second rotation, E. C. C, etc. are added to a track (n) and recorded W1 continuously in sectors n -n . Subsequently, one track is jumped in a sector of n , a restored data by E. C. C is compared with the original data d1 by a read-out cycle R1, and if there is no error, a data d2 which has been transferred to BM2 is recorded W2 by adding E. C. C, etc. in order of sectors n , n , (n+1) ...(n+1) . Next, in a sector (n+1) , one track is jumped and the recording W2 is read out, compared with the original data d2, and if there is an error in some one sector, its data is recorded again in the sector (n+1) , and a data d3 is recorded W3 in sectors (n+1) -(n+2) .

Recording system of information storage device

PURPOSE:To shorten the reaction time, and to improve the purity of the product in the preparation of an aminoalkylthiol useful as a raw material of pharmaceuticals by the hydrolysis of 2-mercaptothiazoline compound, by terminating the reaction at a specific range of conversion. CONSTITUTION:The objective compound of formula II (R , R , R and R are H, lower alkyl or hydroxy-substituted lower alkyl) is prepared in high purity, by hydrolyzing a 2-mercaptothiazoline compound of formulaIwith a hydrohalogenic acid (HX), terminating the reaction when the conversion reaches 80-95%, and recrystallizing the resultant crude aminoalkylthiol with an organic solvent. The hydrohalogenic acid is e.g. hydrofluoric acid, hydrochloric acid, etc., and its amount is 4-8mol per 1mol of the 2-mercaptothiazoline compound. EFFECT:The hydrolytic conversion of as high as 80-95% can be attained easily by suppressing the successive reaction through intermediates and carrying out the direct reaction preferentially.

Preparation of aminoalkylthiol

PURPOSE: To obtain aminoethanesulfonic acid by reacting chloroethylamine hydrochloride with sodium sulfite and treating the liq. reaction product in an electrodialytic bath provided with combined anion and cation exchange membranes to separate effectively aminoethanesulfonic acid from the reaction product. CONSTITUTION: An electrodialytic bath 1 is divided into plural desalted soln. chambers 2 and concd. soln. chambers 3 by alternately stretching cation exchange membranes C and anion exchange membranes A. A soln. 6 of aminoethanesulfonic acid contg. inorg. impurities produced by reacting chloroethylamine hydrochloride with sodium sulfite is fed to the chambers 2, an electrolyte soln. 7 is fed to the chambers 3, and DC is supplied between electrodes 4, 5. The impurities move to the chambers 3, and a concd. and desalted soln. 8 of aminoethanesulfonic acid almost free from impurities is obtd. in the chambers 2. Conditions during electrodialysis include ≤about 60°C temp. of the solns. and about 4.5A/dm 2 current density. COPYRIGHT: (C)1986,JPO&Japio

Manufacture of aminoethanesulfonic acid

PURPOSE:As a mixture of a halogenated alkylamine and carbon disulfide is kept at a constant low temperature, an alkali hydroxide is added dropwise, then the temperature is raised to effect the reaction, thus the titled compound used as an intermediate of drugs is produced in high purity with inhibition of side- reactions in high yield. CONSTITUTION:A halogenated alkylamine hydrohalide acid salt of formulaI (R1-R4 are H, lower alkyl; X, Y are halogen) and an equimolar or slightly excessive amount of carbon disulfide are mixed and an aqueous solution of alkali hydroxide is added to the mixture dropwise at such a rate as the mixture is kept at a temperature lower than 20 deg.C, preferably lower than 10 deg.C. Usually, the dropping time ranges from 30min to 3hr. After completion of dropping, the reaction is effected at 40-80 deg.C to give the objective compound of formula II. Since a water-soluble surface active agent exists in the reaction mixture, the dispersibility or emulsifiability of carbon disulfide is increased to raise its contact efficiency and its reaction efficiency.

Production of 2-mercapto-2-thiazoline

PURPOSE:To prepare the titled compound useful as a raw material of pharmaceuticals, etc., in high purity and yield, by hydrolyzing 2-(2'-mercaptoethylamino)-2-thiazoline hydrohalide derivative with hydrohalogenic acid until the conversion reaches a specific level. CONSTITUTION:The objective compound of formula II is prepared by hydrolyzing a 2-(2'-mercaptoethylamino)-2-thiazoline hydrohalide derivative of formulaI (R1- R4 are H, lower alkyl or hydroxy-substituted lower alkyl; X is halogen) with hydrohalogenic acid. The hydrolysis is stopped when the conversion to the objective compound reaches 75-79%, and the resultant crude aminoalkylthiols are recrystallized in an organic solvent. The crude product remaining in the recrystallization mother liquor after the cystallization is recovered and recycled to the hydrolysis step.

Preparation of aminoalkylthiols

PURPOSE:To separate the objective compound effectively from the reaction liquid of chloroethylamine hydrochloride with sodium sulfite, by cooling the produced reaction liquid at a specific temperature, thereby crystallizing the objective compound CONSTITUTION:Aminoethanesulfonic acid useful as a raw material of pharmaceuticals or dyes is produced by the reaction of chloroethylamine hydrochloride with sodium sulfite In the above process, the produced reaction liquid containing the objective compound and by-produced sodium chloride and sodium sulfate produced by the oxidation of said compound or existing in the sodium sulfite used as a raw material, is cooled at 13-35 degC, preferably 15-20 degC to effect the selective crystallization of the objective compound The objective compound having high purity can be produced economically on an industrial scale, effectively suppressing the contamination with said inorganic salts

Nakamura Hideo

Papers

Preparation of aminoalkylthiol

Manufacture of aminoethanesulfonic acid

Production of 2-mercapto-2-thiazoline

Preparation of aminoalkylthiols

Production of aminoethanesulfonic acid