Preparation of a Select Tautomer of Various Unsymmetrical 1,3,5-Pentanetriones, (1Z,4Z)-1-(Aryl)-1,5-dihydroxy-5-phenylpenta-1,4-dien-3-ones, a 4H-1-benzothiopyran-4-one, and a 2-
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- 作者：Phillip J. Chase Mabe ; Shabree L. Knick ; William G. Shuler ; Sarah S. Carlisle ; Ellyn A. Smith ; Andrew J. Puciaty ; Thomas M. C. McFadden ; Chandra Potter ; Clyde R. Metz ; Charles F. Beam ; William T. Pennington ; Donald G. VanDerveer ; Colin D. McMillan
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2015
- 出版时间：July 29, 2015
- 年：2015
- 卷：54
- 期：29
- 页码：7207-7211
- 全文大小：257K
- ISSN：1520-5045
文摘
Deprotonation of 1-benzoylacetone with excess lithium hexamethyldisilazide (LHMDS) or lithium diisopropylamide (LDA) resulted in a dilithium dianion-type intermediate, which underwent a Claisen-type condensation with substituted aromatic esters or an isatoic anhydride to afford unsymmetrical 1,3,5-pentanetriones or a cyclized heterocyclic product when the C-acylated intermediates contained a select ortho-substituted phenacyl pendant group. Spectral data indicated that a particular tautomer, a (1Z,4Z)-1-(4-aryl)-1,5-dihydroxy-5-phenylpenta-1,4-dien-3-one, resulted upon recrystallization of the linear products. Condensation鈥揷yclization of the dianion-type intermediate with methyl thiosalicylate resulted in a phenacyl benzoheterocyclic thiopyranone and with 5-chloroisatoic anhydride in a phenacyl quinolinone. X-ray crystal analysis of several products afforded additional proof of structure, especially regarding which tautomer was isolated.