- RESORCINOL DERIVATIVES FOR THEIR COSMETIC USE
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The invention relates to resorcinol derivatives of formula (I) and also the salts thereof, the solvates thereof and the optical and/or geometrical isomers thereof, including enantiomers and diastereoisomers, and the racemic mixtures thereof, alone or as a mixture. The invention also relates to a cosmetic process for depigmenting, lightening and/or bleaching keratin materials, especially the skin, using these compounds (I).
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Page/Page column 19
(2018/12/13)
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- P-Toluenesulfonic acid-Celite as a reagent for synthesis of esters of alkylphosphonic acids under solvent-free conditions
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The coupling reaction of alkylphosphonic acids and alcohols on the surface of p-toluenesulfonic acid-Celite under mild and solvent-free conditions gave the corresponding phosphonates in excellent yields. This method provides a useful rapid synthesis of phosphonates for use in the unambiguous identification of chemical warfare agents.
- Gupta, Arvind K.,Kumar, Rajesh,Dubey, Devendra K.,Kaushik
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p. 328 - 331
(2008/02/10)
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- Alkali metal alkoxide clusters: Convenient catalysts for the synthesis of methylphosphonates
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Alkali metal alkoxides are good catalysts (1-8 mol %) for promoting the interchange reaction between carbonyl and phosphorus esters. This reactivity leads to convenient methodologies for the synthesis of symmetric and unsymmetric alkyl-substituted methylphosphonates from dimethyl methylphosphonate (DMMP). Reactions rates are high with initial turnover frequencies (N(t)) in excess of 1 x 106 h-1 observed and with KO(t)Bu > NaO(t)Bu > LiO(t)Bu. The reactions were sensitive to steric effects in the product methylphosphonates with reaction rates paralleling the size of the transferring alkoxide (n-alkyl > isoalkyl >> tert-alkyl). For the test reaction DMMP + isopropyl acetate, substitution kinetics were consistent with a scenario wherein each methoxide is replaced sequentially, and the substitution rate for the second displacement is substantially slower than the first. Kinetic studies on the first substitution process were indicative of a concentration dependent rate law; a scenario most easily accounted for by a coupled transesterification wherein alkoxide reversibly and independently adds to phosphonate and ester.
- Kissling, Rebecca M.,Gagne, Michel R.
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p. 1585 - 1590
(2007/10/03)
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- CATHODE-CATALYZED TRANSESTERIFICATION OF ALKYLPHOSPHONATES
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The cathodic electrolysis of aliphatic alcohols and alkylphophonates in acetonitrile with 0.5 N Et4NClO4 as the base electrolyte leads to mono- and ditransesterified phosphonates.The yield and ratio of these products is a function of the nature of the sta
- Niyazymbetov, M. E.,Kostizella, B.,Keitel, I.,Schwartz, K. H.
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p. 182 - 186
(2007/10/02)
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