Sodium glycolate problems

Yields of propylene chlorohydrin range from 87—90% with dichloropropane yields of 6—9%. The dichloropropane is not only a yield loss but also represents a disposal problem as few uses are known for this material. Since almost all the propylene chlorohydrin is dehydrochlorinated to propylene oxide with lime or sodium hydroxide, none of the chlorine appears in the final product. Instead, it ends up as dilute calcium or sodium chloride solutions, which usually contain small amounts of propylene glycol and other organic compounds that can present significant disposal problems. 

The problem of distinguishing between carbenoid and carbonium ion mechanisms of decomposition of diazoalkanes in protic media arises also in interpreting the base-induced decomposition of tosylhydrazones. In the original procedure for this widely-used reaction (W. R. Bamford and Stevens, 1952), the tosylhydrazone of a carbonyl compound is treated with the sodium salt of ethylene glycol in refluxing glycol. A mixture of olefins and alkoxyethanol is produced (equation 6). Many... 

In contrast to aqueous methods, the polyol approach resulted in the synthesis of metallic nanoparticles protected by surface-adsorbed glycol, thus minimizing the oxidation problem The use of polyol solvent also reduces the hydrolysis problem of ultrafine metal particles, which often occurs in aqueous systems. Oxide nanoparticles can be prepared, however, with the addition of water, which makes the polyol method act more like a sol—gel reaction (forced hydrolysis). For example, 5.5-nm CoFe204 has been prepared by the reaction of ferric chloride and cobalt acetate in 1,2- propanediol with the addition of water and sodium acetate. 

The extensive use of perio te, fi uently sodium periodate, as oxidants for water insoluble glycols in contemporary organic synthesis contradicts the recommendation made earlier that LTA is the preferred reagent. Hydiophobicity of the substrates does not appear to pose problems since they are readily soluble in aqueous solvents. In addition, periodate cleavage can proceed in a two-phase mixture, indicated in... 

PIH after a peel with 70% unbuffered glycolic acid neutralization with a sodium bicarbonate solution as soon as erythema appeared. There is no visible frosting. Postoperative developments were normal. On the 8th day, the patient consulted the doctor about the appearance of PIH 3 days before (a). Treatment consisted of tyrosinase inhibitors, topical antioxidants, sun avoidance and protection, (b) The patient after 5 weeks, (c) After 8 weeks. The hyperpigmentation has improved significantly. A telephone call revealed that the problem has cleared up completely after 3 months. 

Although MEEP-metal salt complexes show high ionic conductivities, these materials have undesirable creep properties at ambient temperatures, thus precluding their use in practical devices. To overcome this problem, one approach has been to synthesize dimensionally stable poly(phosphazenes) by crosslinking poly-[(chloro)(methoxy ethoxy ethoxy) phosphazene] with polyethylene glycol). If some of the chlorines in poly(dichlorophosphazene) are left unsubstituted after the initial reaction with the sodium salt of methoxy ethoxy ethanol, these can be reacted further with the difunctional poly(ethylene glycol)to afford crosslinked materials (Eq. 13 and Scheme 14) [204]... 

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