- A New method of synthesizing phenalen-1-one: Reduction of 3-hydroxyphenalen-1-one using nabh4 and lanthanoid chlorides
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Phenalen-1-one was obtained in considerable yield by reducing 3-hydroxyphenalen-1-one. Most of known preparation methods are not very practical, either because their yields are very poor or because their processes have many steps. This regioselective 1,2-reduction proceeded by the action of NaBH4 and various cations of rare-earth elements and metals. The yields of phenalen-1-one were examined as a function of typical lanthanoids, molar ratios of lanthanoid ions to 3-acetoxy-phenalen-1-one, and differing methods of protecting the hydroxyl group. Lanthanum chloride (LaCl3) gave the greatest yield (45.3%) of phenalen-1-one at molar ratios higher than a third, probably because La3+ ion is a hard acid and coordinates easily to a hard solvent such as methanol. Further, it has the largest ionic radius among all lanthanoid ions. Copyright Taylor & Francis Group, LLC.
- Sawada, Tadanobu,Ishii, Hiroyuki,Ueda, Toyotoshi,Aoki, Junji
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experimental part
p. 3912 - 3923
(2009/12/08)
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- A new cephalosporin. SCE-963: 7-[2-(2-aminothiazol-4-yl)-acetamido]-3- [[[1-(2-dimethylaminoethyl)-1h-tetrazol-5-yl]-thio]methyl]ceph-3-em-4-carboxylic acid. Chemistry and structure-activity relationships
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The synthesis and the in vitro and in vivo antimicrobial activities of a series of 7-[2-(2-aminothiazol-4-yl)acetamido]cephalosporins (1) having varied 3-substituents, such as methyl, hydroxymethyl, acetoxymethyl, pyridiniomethyl and heterocyclicthiomethyls, are described. The derivates having five membered heterocyclicthiomethyls exhibited strong inhibitory activities against Gram-negative organisms including some strains od Escherichia coli and Proteus morganii which are insensitive to cefazolin and cephaloridine. Pronounced activities were noted with 7-[2-(2-aminothiazol-4-yl)-acetamido]-3-[[[1-(2-dimethylaminoethyl)-1H-tetra zol-5-yl]thio]methyl]ceph-3-em-4-carboxylic acid (1y;SCE-963).
- Numata,Minamida,Yamaoka,Shiraishi,Miyawaki,Akimoto,Naito,Kida
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p. 1262 - 1271
(2007/10/09)
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