Sulfuric esters, preparation

Fig. 7. Combined sulfur during preparation of cellulose acetate hydrolysis of sulfate and esters (6). Acetylation schedule A, mixer charged with linters and acetic acid B, minor portion of catalyst added C, began cooling to 18°C D, acetic anhydride added and continued cooling to 16°C E, significant portion...

Cl Reactive Blue 19 (9) is prepared by the reaction of bromamine acid (8) with y -aminophenyl-P-hydroxyethylsulfone [5246-57-1] (76) ia water ia the presence of an acid-hinding agent such as sodium bicarbonate and a copper catalyst (Ullmann condensation reaction) and subsequent esterification to form the sulfuric ester. 

Differences in heats of formation of the two kinds of Nitrostarch are regarded by these authors as related to the presence of sulfuric esters in the Nitrostarches prepared by means of mixed acids... 

A variety of sulfating agents has been used for preparing sulfuric esters of polysaccharides.297 - 303 The methods employed include use of adducts of sulfur trioxide with such aprotic solvents as triethylamine,299 dimethyl... 

Preparative hazard See Diethylzinc Sulfur dioxide See related SULFUR ESTERS C4Hio04S2Zn Zn[0S( 0)Et]2... 

An important method for preparing aziridine (ethylene imine) and its derivatives is to cyclize the sulfuric esters of ethanolamines by heating them... 

Nitrated cellulose acetate has been prepared, and nucleophilic replacement of nitrate groups of cellulose nitrate with halides has been performed. Oxidative decomposition of cellulose nitrate into a water-soluble material may be brought about by aqueous digestion at high temperature and high pressures, and this finds particular application in the determination of small proportions of the sulfate in cellulose nitrate. A route for the replacement of nitric ester groups in cellulose nitrate by sulfuric ester groups has been reported. ... 

Since the exocyclic sulfur is more reactive in the ambident anion than in A-4-thiazoIine-2-thione. greater nucleophilic reactivity is to be expected. Thus a large variety of thioethers were prepared in good yields starting from alkylhalides (e.g.. Scheme 38 (54, 91, 111, 166-179). lactones (54, 160), aryl halides (54, 152. 180, 181), acyl chlorides (54. 149, 182-184). halothiazoles (54, 185-190), a-haloesters (149. 152. 177. 191-194), cyanuric chloride (151). fV.N-dimethylthiocarbamoyl chloride (151, 152. 195. 196), /3-chloroethyl ester of acrylic acid (197), (3-dimethylaminoethyl chloride (152). l,4-dichloro-2-butyne (152), 1,4-dichloro-2-butene (152), and 2-chloro-propionitrile (152). A general... 

Polythiodipropionic acids and their esters are prepared from acryUc acid or an acrylate with sulfur, hydrogen sulfide, and ammonium polysulfide (32). These polythio compounds are converted to the dithio analogs by reaction with an inorganic sulfite or cyanide. 

Direct, acid catalyzed esterification of acryhc acid is the main route for the manufacture of higher alkyl esters. The most important higher alkyl acrylate is 2-ethyIhexyi acrylate prepared from the available 0x0 alcohol 2-ethyl-1-hexanol (see Alcohols, higher aliphatic). The most common catalysts are sulfuric or toluenesulfonic acid and sulfonic acid functional cation-exchange resins. Solvents are used as entraining agents for the removal of water of reaction. The product is washed with base to remove unreacted acryhc acid and catalyst and then purified by distillation. The esters are obtained in 80—90% yield and in exceUent purity. 

The sulfur amino acid content of soy protein can be enhanced by preparing plasteins from soy protein hydrolysate and sources of methionine or cystine, such as ovalbumin hydrolysate (plastein AB), wool keratin hydrolysate (plastein AC), or L-methionine ethyl ester [3082-77-7] (alkaU saponified plastein) (153). Typical PER values for a 1 2 mixture of plastein AC and soybean, and a 1 3 mixture of alkah-saponified plastein and soybean protein, were 2.86 and 3.38, respectively, as compared with 1.28 for the soy protein hydrolysate and 2.40 for casein. 

---