179487-56-0Relevant articles and documents
A convenient approach to an advanced intermediate toward the naturally occurring, bioactive 6-substituted 5-hydroxy-4-aryl-1H-quinolin-2-ones
Simonetti, Sebastián O.,Larghi, Enrique L.,Kaufman, Teodoro S.
supporting information, p. 2625 - 2636 (2016/03/05)
5-Hydroxy-4-aryl-3,4-dihydro-1H-quinolin-2-ones are a small family of natural products isolated from fungal strains of Penicillium and Aspergillus. Most of its members, which are insecticides and anthelmintics, carry an isoprenoid C-6 side chain. The synthesis of a 6-propenyl-substituted advanced intermediate for the total synthesis of these natural products is presented in this paper. This was achieved through the stereoselective construction of a β,β-diarylacrylate derivative from 6-nitrosalicylaldehyde, using a Wittig olefination and a Heck-Matsuda arylation, followed by a selective Fe0-mediated reductive cyclization. Installation of the 6-propenyl side chain was performed by 5-O-allylation of the heterocycle, followed by Claisen rearrangement and conjugative migration of the allyl double bond, as the key steps. The Grubbs II-catalyzed olefin cross metathesis of the 6-allyl moiety with 2-methylbut-2-ene to afford a precursor of peniprequinolone is also reported.
Wittig reactions in water media employing stabilized ylides with aldehydes. Synthesis of α,β-unsaturated esters from mixing aldehydes, α-bromoesters, and Ph3P in aqueous NaHCO3
El-Batta, Amer,Jiang, Changchun,Zhao, Wen,Anness, Robert,Cooksy, Andrew L.,Bergdahl, Mikael
, p. 5244 - 5259 (2008/02/07)
(Chemical Equation Presented) Water is demonstrated to be an effective medium for the Wittig reaction over a wide range of stabilized ylides and aldehydes. Despite sometimes poor solubility of the reactants, good chemical yields normally ranging from 80 to 98% and high E-selectivities (up to 99%) are achieved, and the rate of the reactions in water is unexpectedly accelerated. The efficiency of water as a medium in the Wittig reaction is compared to conventional organic solvents ranging from carbon tetrachloride to methanol. The aqueous Wittig reaction works best when large hydrophobic entities are present, such as aromatic, heterocyclic aromatic carboxaldehydes, and long-chain aliphatic aldehydes with triphenylphosphoranes. The E/Z-isomeric ratio of the Wittig products appears dependent on the electron-accepting/donating capacity and the location of the substituents present in the aromatic ring. The effect of additives, such as benzoic acid, LiCl, and sodium dodecyl sulfate (SDS), on the Wittig reaction has been explored. The Wittig reaction can also be conducted in the presence of acidic entities, such as phenols and carboxylic acids. In addition, large α-substituents in the aliphatic aldehydes do not jeopardize the reaction. It is also demonstrated that hydrates of aldehydes can be used directly in the aqueous Wittig reaction as substrates. The scope of the aqueous Wittig reaction is extended to 24 examples of one-pot mixtures of Ph3P, α-bromoesters, and aldehydes in sodium bicarbonate solution (at 20°C for 40 min to 3 h) to provide Wittig products of up to 99% yield and up to 98% E-selectivity. Since water is inexpensive, extremely easy to handle, and represents no environmental concerns, it should be considered a possible medium for new organic reactions.
Anti-inflammatory benzoic acid derivatives
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, (2008/06/13)
Novel benzoic acid derivatives have the formula: STR1 wherein --X-- represents C1 to C6 alkylene, C2 to C6 alkenylene or a divalent moiety having the structure --(CH2)m --Z-- in which m is an integer from 0 to 3 and Z represents --O--, --S-- or --NH--; --Y-- represents a direct bond, C1 to C6 alkylene, C2 to C6 alkenylene or a divalent moiety having the structure --(CH2)m --Z--(CH2)n in which m and n are each, independently, an integer from 0 to 3 and --Z-- represents --O--, --S-- or --NH--; R represents a 5- or 6-membered carbocyclic or heterocyclic ring or a carbocyclic or heterocyclic fused ring system containing up to 10 members in the ring, which carbocyclic, heterocyclic or fused ring system may be saturated or unsaturated and may contain up to two substituents selected from lower alkyl, methoxy, halo and trifluoromethyl; and R1 and R2 are each, independently, selected from hydrogen, lower alkyl, methoxy, halo and trifluoromethyl. The benzoic acid derivates are useful as anti-inflammatory agents.
