Sodium hypochlorite treatments

Inaba D, Ruben J, Takagi O and Arends J (1996) Effect of sodium hypochlorite treatment on remineralization of human root dentine in vitro. Caries Res 30, 218-224. 

Preparation of the prototype drug departs from the phenylenediamine strategy used in all of the previous examples. Condensation of thiazolo nitrile (53-2) with aniline catalyzed by aluminum chloride affords the amidine addition product (53-3). This is then converted to its reactive A -chloro derivative (53-4) by reaction with sodium hypochlorite. Treatment of that intermediate with a base such as potassium hydroxide leads directly to the cyclization product and thus the benzimidazole thiabendazole (53-6) [56]. The reaction can be rationalized by invoking as the first step the abstraction of chloride to leave behind a nitrene species such as (53-5) this would then readily insert in the CH bond at the ortho position. 

The H-D exchange rates of a series of a-methylazines, including 2-methylquinoxaline, have been determined. " The anion of 2-methylquinoxaline generated in liquid ammonia with potassamide reacts with n-propyl nitrate to give 2-nitromethylquinoxaline (50) in 58% yield." " 2-Dichloronitromethylquinoxaline (51) is formed when 2-nitromethylquinoxaline is treated with sodium hypochlorite." Treatment of 2,3-dimethylquinoxaline with sodamide in hexamethylphosphoramide (HMPT) similarly gives a dianion which on reaction with methyl iodide is converted into 2,3-diethylquinoxaline in 75% yield." ... 

Sodium Hypochlorite Treatment. This treatment was considered because sodium hypochlorite is often used to sterilize plant tissues prior to microbiological studies. Since the disease... 

Figure 7. A bar graph of the observed levels of psoralen, bergapten, xanthotoxin, and isopimpinellin in celery cv. 5270-R 72 h after UV light and sodium hypochlorite treatment.

Although all samples became discolored by the treatment, only the 20% NaOH resulted in an observable loss of strength. Table 10.3 Sodium hypochlorite treatment of the samples ... 

MountDuris, G., Silikas. N., and Eliades, G. (2004) Effect of sodium hypochlorite treatment on the molecular composition and morphology of human coronal dentin. /. Adhes. Dent, 6 (3), 175—182. Oook, S. et oL (2004) Influence of polymerization mode of dual-polymerized resin direct core foundation systems on bond strengths to bovine dentin. 

By treatment of an amide with sodium hypobromite or sodium hypochlorite solution (or with the halogen and alkali), the amine of one less carbon atom is produced, the net result being the elimination of the carbonyl group. An example is ... 

Raw lac is first treated to remove water-soluble carbohydrates and the dye that gives lac its red color. Also removed are woody materials, insect bodies, and trash. It is further refined by either hot filtration or a solvent process. In the heat process, the dried, refined lac is filtered molten through cloth or wine screens to produce the standard grades of orange shellac. In the solvent process, lac is dissolved and refluxed in alcohol solvents, filtered to remove dirt and impurities, and concentrated by evaporation. The lac can be further decolori2ed in this process to produce very pale grades. Bleached shellac is prepared by treatment with dilute sodium hypochlorite and coalesced into slabs. 

Superchlorination typically refers to a dding FAC equal to 10 x ppm CAC, whereas shock treatment generally involves addition of 10 ppm FAC. The frequency of superchlorination or shock treatment depends on bather load and temperature. Calcium hypochlorite, because of its convenience, is widely used for superchlorination and shock treatment. Sodium hypochlorite, LiOCl, or chlorine gas are also used. Chloroisocyanurates are not recommended since their use would result in excessive cyanuric acid concentrations. 

The refining process most commonly used involves treatment with hot aqueous alkaH to convert free fatty acids to soaps, followed by bleaching, usually with hydrogen peroxide, although sodium chlorite, sodium hypochlorite, and ozone have also been used. Other techniques include distillation, steam stripping, neutralization by alkaH, Hquid thermal diffusion, and the use of active adsorbents, eg, charcoal and bentonite, and solvent fractionation... 

The largest use of calcium hypochlorite is for water treatment. It is also used for I I and household disinfectants, cleaners, and mildewcides. Most of the household uses have been limited to in-tank toilet bowl cleaners. In areas where chlorine cannot be shipped or is otherwise unavailable, calcium hypochlorite is used to bleach textiles in commercial laundries and textile mills. It is usually first converted to sodium hypochlorite by mixing it with an aqueous solution of sodium carbonate and removing the precipitated calcium carbonate. Or, it can be dissolved in the presence of sufficient sodium tripolyphosphate to prevent the precipitation of calcium salts. However, calcium hypochlorite is not usually used to bleach laundry and textiles because of problems with insoluble inorganic calcium salts and precipitation of soaps and anionic detergents as their calcium salts. 

Oxidative surface treatment processes can be gaseous, ie, air, carbon dioxide, and ozone Hquid, ie, sodium hypochlorite, and nitric acid or electrolytic with the fiber serving as the anode within an electrolytic bath containing sodium carbonate, nitric acid, ammonium nitrate, ammonium sulfate, or other electrolyte. Examples of electrolytic processes are described in the patent Hterature (39,40)... 

High yields of NaOCl are obtained electrolyticaHy by oxidation of CT at dimensionally stable anodes (219). Sodium hypochlorite is prepared using small diaphragmless or membrane cells, with a capacity of 1—150 kg/d of equivalent CI2, which produce a dilute hypochlorite solution of 1—3 and 5—6 g/L from seawater and brine, respectively (see Chemicals from brine). They are employed in sewage and wastewater treatment and in commercial laundries, large swimming pools, and aboard ships. 

Water from cooling tower pump suction, pH 8.6-8.8, pressure 20-30 psi (140-210 kPa), flow 2-5 ft/s (0.2 to 1.5 m/s). Dispersant, 1-3 ppm tolyltriazole, sodium hypochlorite 2 hr/day to 0.8 free residual chlorine 0.6-0.8 ppm total zinc and 0.1-0.2 ppm soluble zinc. Free chlorine maintained at 1 ppm for 5 consecutive days/month during the summer. Chemical treatment started after 2 years of no treatment. Water conductivity -612 ( imhos/cm), turbidity 27 NTU (nephelometric turbidity units), chloride 110 ppm, sulfate 50 ppm, carbonate alkalinity (CaCOa) 27 ppm, bicarbonate alkalinity (CaCOs) 118 ppm... 

Seek alternatives to chlorine for water treatment and disinfecting applications. For example, sodium hypochlorite has been used both in industrial and municipal water treatment applications (Somerville, 1990). Other alternatives include calcium hypochlorite, ozone, ultraviolet radiation and heat treatment (Negron, 1994 Mizerek, 1996). 

The required A-chloroamines 9 can be prepared from the corresponding amine by treatment with sodium hypochlorite or A-chlorosuccinimide. 

Intermediate arylamidine, 6S, is prepared by the aluminum chloride-catalyzed addition of aniline to the nitrile function of 4-cyanothiazole (67), Amidine, 65, is then converted to its N-chloro analog (69) by means of sodium hypochlorite. On base treatment, this apparently undergoes a nitrene insertion reaction to produce thiabendazole (70), ... 

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