- Xanthines, optionally incorporated in liposomes, for promoting skin or hair pigmentation
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A method of treating skin or hair for promoting pigmentation wherein a xanthine component, in an amount effective to promote pigmentation, is incorporated in liposomes or hydrated lipidic lamellar phases.
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- Les systemes biphasiques. 3. Alkylation des purines en catalyse par transfert de phase (1a)
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The phase transfer catalysed methylation of adenine gave selectively 9-methyladenine (98percent), while benzylation yields 9-benzyladenine as the major product accompanied by very small amounts of the 3-isomer.Alkylation of xanthine, theobromine and theophylline by the same technique gave also the corresponding N.alkyl derivatives in high yields, with no other O-alkylated regioisomer.These alkylation procedures, owing to their simplicity and selectivity, constitute a considerable improvement upon classical techniques.
- Hedayatullah, Mir
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p. 249 - 251
(2007/10/02)
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