- Synthesis of a P-Glycoprotein Inhibitor and Its High-Energy (Z)-Isomer by Carbenoid Eliminative Cross-Coupling
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To gauge the feasibility of carbenoid eliminative cross-coupling for the synthesis of polyfunctional alkenes, a P-glycoprotein inhibitor containing an (E)-configured 4-chromanylidene-type trisubstituted olefin was prepared as well as its previously undescribed (Z)-isomer. Stereospecific alkene synthesis required generation of functionalized enantioenriched α-metalated carbamates [R1R2CM(O2CNi-Pr2), M = Li or Bneo], and problems associated with incorrect lithiation regioselectivity and unexpected organolithium configurational lability were encountered. Solutions to these difficulties are described together with a method for ee determination of α-carbamoyloxyboronates.
- Tanpure, Subhash D.,El-Mansy, Mohamed F.,Blakemore, Paul R.
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- Acid activated montmorillonite K-10 mediated intramolecular acylation: Simple and convenient synthesis of 4-chromanones
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3-Aryloxyproionic acids undergo intramolecular cyclization in the presence of AA.Mont.K-10 in toluene under reflux for 30–45 min in good to excellent yields. Phenyl ring bearing various substituents at the ortho, meta, para positions undergo this cyclization reaction. This method involves simple work up and amenable for large scale preparations. The heterogeneous acid treated catalyst can be regenerated and used for up to three cycles with minimum loss of activity.
- Begum, Ayisha F.,Balasubramanian, Kalpattu K.,Shanmugasundaram, Bhagavathy
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- 5-AMINO- 4-HYDROXYPENTOYL AMIDES
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HIV inhibitors of formula (I) wherein R1 is halo, C1-4alkoxy, trifluoromethoxy; R2 is a group of formula (A); R3 is a group of formula (B); R4 is a group of formula (C); n is 0 or 1; A is CH or N; R5 and R6 are hydrogen, C1-4alkyl, halo; R7 and R8 are C1-4alkyl or C1-4alkoxyC1-4alkyl; R9 is C1-4alkyl, cyclopropyl, trifluoromethyl, C1-4alkoxy, or dimethylamino; R10 is hydrogen, C1-4alkyl, cyclopropyl, trifluoromethyl, C1-4alkoxy, or dimethylamino; pharmaceutically acceptable addition salts and solvates thereof; pharmaceutical compositions containing these compounds as active ingredient and processes for preparing said compounds.
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Page/Page column 30
(2011/06/26)
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- THERMAL BEHAVIOUR OF ARYL γ-HALOPROPARGYL ETHERS
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A systematic study of the behaviour of aryl γ-halopropargyl ethers under thermal condition was undertaken.Aryl γ-bromopropargyl ethers 2 underwent unique transformation in N,N-diethylaniline (215 deg C, 6 h) giving rise to a mixture of products 3,4 and 5,whereas, under similar conditions aryl γ-chloropropargyl ethers 8, afforded 4-chlorochromenes, 9.A remarkable substituent and solvent effect has been observed in the thermolysis of these aryl γ-bromo and γ-chloropropargyl ethers, rendering this transformation as a method for the synthesis of a number of substituted 4-bromochromenes 3, 4-chlorochromenes 9 and chroman-4-ones 7.In contrast, solution thermolysis of aryl γ-iodopropargyl ether 11 afforded aryl propargyl ether 1 as the major product.
- Ariamala, G.,Balasubramanian, K. K.
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p. 309 - 318
(2007/10/02)
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- A SIMPLE ROUTE FOR THE SYNTHESIS OF 4-CHLOROCHROMENES AND CHROMAN-4-ONES
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A one pot synthesis of a number of 4-chlorochromenes and chroman-4-ones was achived from γ-chloropropargyl aryl ethers proceeding through Claisen rearrangement, depending upon the solvent of choice.
- Ariamala, G.,Balasubramanian, K.K.
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p. 3487 - 3488
(2007/10/02)
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