Esters color development

A measure of the color developed by impurities when trimeUitate esters are produced can be correlated with the anhydride color measurement. The method measures the color difference in light transmittance between a trimellitic solution and a 3.0 N sodium hydroxide solution as a reference. The difference in light transmittance or AH (total color difference) is obtained using a colorimeter. 

C. Crotyl diazoacetate. A solution of 10.0 g. (0.038 mole) of the />-toluenesulfonylhydrazone of glyoxylic acid chloride in 100 ml. of methylene chloride is cooled in an ice bath. Crotyl alcohol (2.80 g. or 0.038 mole) (Note 7) is added to this cold solution, and then a solution of 7.80 g. (0.077 mole) of redistilled triethyl-amine (b.p. 88.5-90.5°) in 25 ml. of methylene chloride is added to the cold reaction mixture dropwise and with stirring over a 20-minute period. During the addition a yellow color develops in the reaction mixture and some solid separates near the end of the addition period. The resulting mixture is stirred at 0° for 1 hour and then the solvent is removed at 25° under reduced pressure with a rotary evaporator. A solution of the residual dark orange liquid in approximately 200 ml. of benzene is thoroughly mixed with 100 g. of Florisil (Note 8) and then filtered. The residual Florisil, which has adsorbed the bulk of the dark colored by-products, is washed with two or three additional portions of benzene of such size that the total volume of the combined benzene filtrates is 400-500 ml. This yellow benzene solution of the diazoester is concentrated under reduced pressure at 25° with a rotary evaporator, and the residual yellow liquid is distilled under reduced pressure. (Caution This distillation should be conducted in a hood behind a safety shield) (Note 9). The diazo ester is collected as 2.20-2.94 g. (42-55%) of yellow liquid, b.p. 30-33° (0.15 mm.), n T) 1.4853 - 1.4856 (Note 10). 

Benzofuran derivatives such as 2-cyanobenzofuran-5-sulfonic acid esters and amides have found wide application as color developers in photographic processes (44USP2350127). The substituted benzofurans (507), (508) and (509) are used as brightening agents in textiles, wool, paper, cellulose and nylon (53MI31201). 

Organophosphate. For the estimation of phosphoric acid esters, the developed plate is sprayed with 0.25% solution of palladium chloride in 0.1 N HC1 and dried in air. After exactly ten minutes, the area of the yellow-brown colored spot developed is measured and compared with that of the spots of standard insecticide solutions run alongside. 

Sulfonyl chlorides have extensive uses in organic synthesis in the preparation of sulfonamides and sulfonate esters. Methanesulfonyl chloride is a key raw material in the synthesis of critical components for photographic color developing formulations, as well as for herbicides and pharmaceuticals. 

To a 125-mL separatory funnel were charged 1 g carbonic acid, methyl 3-phenylbenzofur-2-yl ester and 20 mL CH2CI2. The solution was effected by swirling. Then 40 mg DMAP was added, and the solution was briefly shaken. During the shaking, a deep blue/purple color developed immediately and disappeared after about 1 min. The solution was then washed successively with 5% HCl (3 x 20 mL) and 100 mL water, dried over MgS04 and con-... 

Chem. Descrip. Aromatic acid phosphate ester Uses Penetrant, dispersant for pigments Features Improves color development of pigments Adekacol CS-1361E [Asahi Denka Kogyo]... 

Other Borohydrides. Potassium borohydride was formerly used in color reversal development of photographic film and was preferred over sodium borohydride because of its much lower hygroscopicity. Because other borohydrides are made from sodium borohydride, they are correspondingly more expensive. Generally their reducing properties are not sufficiently different to warrant the added cost. Zinc borohydride [17611-70-0] Zn(BH 2> however, has found many appHcations in stereoselective reductions. It is less basic than NaBH, but is not commercially available owing to poor thermal stabihty. It is usually prepared on site in an ether solvent. Zinc borohydride was initially appHed to stereoselective ketone reductions, especially in prostaglandin syntheses (36), and later to aldehydes, acid haHdes, and esters (37). 

Other applications dealt with the development of a luciferin ester substrate to measure the luciferase activity in living cells [141], the detection of toxic compounds such as sodium azide, fluoroacetic acid, and antibiotics [142], the development of a biosensor for the determination of bioavailable mercury [143], the use of eukaryotic luciferases as bacterial markers with different colors of luminescence [144], the determination of complement-mediated killing of bacteria [145], and the development of a bioassay for the determination of HIV type 1 virus and HIV-1 Tat protein activity, valuable also for analysis of HlV-inhibi-tory agents [146],... 

Plastic pellets, threat from, 20 231 Plastic pumps, for corrosive liquids, 21 76 Plastic refractories, 21 482 Plastics. See also Styrene plastics adhesion of coatings to, 7 91-92 advanced materials, 1 693 cellulose ester applications, 5 404 chemical exposure tests on, 19 583 citric acid application, 6 648 colloidal suspensions, 7 273t colorants for, 7 358-380 development of, 10 168... 

Other evidence indicating true ionic polymerisation was found in some reactions in which, because of the relatively low molar ratio [styrene]/[HC104], the styrene sequestered by complexing with the ester was a considerable fraction of the total [styrene], and therefore the colour developed while there was still an appreciable concentration of monomer. In these experiments the reaction curves showed a marked kink, corresponding to a spectacular increase in rate, just at the instant of color formation, and the previously very slow polymerisation was brought to completion in a few seconds from this time. 

---