- Photochemistry of matrix-isolated 5-cyano-2H-pyran-2-one (δ-cyano-α-pyrone) and cyanocyclobuta-1,3-diene
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Matrix-isolation photochemistry ( > 299 nm; Ar, 10 K) of 5-cyano-2H-pyran-2-one (5, -cyano - pyrone) shows complete conversion to a mixture of several ring-opened ketene isomers (6) and a ring-closed Dewar lactone (7), as detected by infrared spectroscopy. Subsequent irradiation ( > 200 nm) causes decarboxylation of the Dewar lactone (7) to produce cyanocyclobuta-1,3-diene (8). Continued irradiation ( > 200 nm) results in the photodecomposition of cyanocyclobuta-1,3-diene (8) to cyanoacetylene and acetylene. 4-Cyanopyridine (10) was explored as an alternative photochemical precursor to cyanocyclobuta-1,3-diene (8). It was found, however, that 10 does not exhibit observable photochemistry under our irradiation conditions.
- Menke, Jessica L.,McMahon, Robert J.
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experimental part
p. 186 - 194
(2011/04/23)
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- Oxidative carbonylation of methanol to dimethyl carbonate by chlorine-free homogeneous and immobilized 2,2′-bipyrimidine modified copper catalyst
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A chlorine-free catalyst, prepared in situ from Cu(II) acetate and 2,2′-bipyrimidine, can be used for the oxidative carbonylation of methanol to dimethyl carbonate. In situ high pressure IR and NMR spectroscopic studies suggest the formation of [Cu(2,2′-bipyrimidine)(CO)(OMe)] as one of the key intermediates. The catalytic performance of the 2,2′-bipyrimidine- modified Cu-catalyst is similar to the CuCl-based system. The chlorine free catalyst can be immobilized by using the copolymer of 5-vinyl-2,2′- bipyrimidine and styrene.
- Csihony, Szilard,Mika, Laszlo T.,Vlad, Gabor,Barta, Katalin,Mehnert, Christian P.,Horvath, Istvan T.
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p. 1094 - 1106
(2008/09/19)
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- NITROGEN-CONTAINING HETEROCYCLIC COMPOUND AND PHARMACEUTICAL APPLICATION THEREOF
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It is intended to provide a compound represented by the general formula (I): (I) (wherein all the symbols are as defined in the description) which has a p38 MAP kinase inhibitory activity, a salt thereof, an N-oxide thereof, a solvate thereof, or a prodrug thereof. The compound of the invention is useful for preventing or treating a disease in which the abnormal production of a cytokine such as an inflammatory cytokine or a chemokine or overreaction to them is considered to be involved in the cause and aggravation of pathological conditions, in other words, an inflammatory disease, a respiratory disease, a cardiovascular disease, a central nervous system disease or the like, which is a cytokine-mediated disease.
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Page/Page column 81
(2010/11/26)
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- A new route for manufacture of 3-cyano-1-naphthalenecarboxylic acid
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3-Cyano-1-naphthalenecarboxylic acid is an intermediate required for manufacture of tachykinin receptor antagonists. The 1,3-disubstitution pattern on the naphthalene skeleton complicates the synthesis of this cyano acid. Previous literature-based chemistry is unattractive for large-scale manufacture due to stoichiometric use of mercury salts, low yield, and other operational difficulties. An attractive new route has been developed by establishing the 1,3-substitution on the carbon atoms destined for only one-half of the naphthalene 2-ring system, via 3-bromocoumalate, and then building up the rest of the naphthalene ring system by Diels-Alder addition of 3-bromocoumalate to in situ-generated benzyne. The resulting 4-bromo-2-naphthoate was converted to the required cyanoacid by transformation of ester to nitrile followed by carbonylation of the bromo substituent. The new route has been scaled up successfully and offers significant advantages over previous literature chemistry in terms of improved process environmental implications, improved yield, lower cost, and improved robustness and ease of operation at larger scales of operation.
- Ashworth,Bowden,Dembofsky,Levin,Moss,Robinson,Szczur,Virica
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- Allo-, Epiallo- and Pseudoyohimbanes as well as Heteroyohimbanes by Reaction of a Tetracyclic Aldehyde with Acetoacetate in Different Solvents
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The reaction of methyl acetoacetate with 4 in CH3OH/ CH3ONa leads to 11 and 12 with yohimbane skeleton but bicyclo ring E.In DMF/ tBuOK, the epialloheteroyohimbane 13 is produced in fairly good yield, whereas in THF/ NaH the allo-19-hydroxyyohimbinone 17 is formed, which undergoes thermal decomposition to the alloyohimb-18-enone 19.Finally, a full description of an early mentioned synthesis of rac-deplancheine (7) is given.
- Rosenmund, Peter,Casutt, Michael,Wittich, Michael
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p. 233 - 238
(2007/10/02)
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- EINE NEUE TOTALSYNTHESE VON (+/-)DEPLANCHEIN
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The key step in this synthesis, basing on the toluene-tricarbonylchrome promoted 1.4-H2 addition on the diene 7, proceeds with nearly 100 percent yield and full stereoselectivity.
- Rosenmund, Peter,Casutt, Michael
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p. 1771 - 1774
(2007/10/02)
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