38474-02-1Relevant academic research and scientific papers
NICOTINAMIDE DERIVATIVES USEFUL AS PDE4 INHIBITORS
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Page/Page column 80-81, (2010/02/10)
This invention relates to nicotinamide derivatives of formula (I) and to pharmaceutical compositions containing, and the uses of such derivatives as PDE4 inhibitors wherein R7 is attached to the 3-or 4-position of the phenyl ring and is S(O)pR8, R8 is (C1-C4)alkyl optionally substituted by (C3-C6)cycloalkyl; m is 0 or 1; L is a (C3-C8)carbocyclic non-aromatic ring; and the remaining variables are as defined in the claims.
Metallation reactions. XX. Regioselective metallation of (alkylthio)methoxybenzenes by superbases versus organolithium compounds
Cabiddu,Fattuoni,Floris,Gelli,Melis
, p. 4965 - 4974 (2007/10/02)
(Alkylthio)methoxybenzenes have been metallated using two different metallating agents. The results show that sometimes superbases and butyllithium do not functionalize the same sites. Superbases monometallate the thiomethylic carbon of meta and para (methylthio)methoxybenzenes. The same substrates on the other hand are metallated by butyllithium in ortho to the methoxy group. One-step dimetallation performed with either superbases or butyllithium occurs at the thiomethylic carbon at the aryl carbon ortho to the methoxy group. Two consecutive one-pot monometallations of the para isomer (1c) with superbases occur at the thiomethylic carbon and at the annular carbon ortho to the methoxy group, in this order. A similar procedure with butyllithium metallates the two ortho positions to the methoxy group. Monometallation of (ethylthio) derivative (1d) yields, products substituted in ortho to the methoxy group using, either superbases or butyllithium. Dimetallation of this compound always substitutes the hydrogen ortho to the methoxy group and a thiomethylenic hydrogen.
METALATION REACTIONS. XIV. REGIOSPECIFIC PREPARATION OF POLYSUBSTITUTED BENZENES VIA MONO- OR DI-LITHIATION REACTIONS OF AROMATIC THIOETHERS
Cabiddu, Salvatore,Fattuoni, Claudia,Floris, Costantino,Gelli, Gioanna,Melis, Stefana,Sotgiu, Francesca
, p. 861 - 884 (2007/10/02)
The preparation of polyfunctionalized aromatic thioethers either by one-step dilithiation or by two successive one-flask monometalation reactions is described.By acting on 1 two equal or different electrophiles one on the thiomethyl group and one in the ortho-position with respect to it are introduced; by acting on 11 and on 35 the substitution involves the thiomethyl carbon atom and that in the ortho-position with respect to the alkoxy group.In the case of the homologeous isopropylthio (23) the substitution involves the two aryl carbon atoms in the ortho-position to both functions.In the case of the p-disubstituted isomers (49, 59) analogous behaviour to ortho isomers in one-step metalation reaction is observed, while the two hydrogen atoms in the ortho-positions to the methoxy group are substituted when two successive monometalations are employed.The metalation of 40 results low selective.The behaviour of 79 and 93 is analogous to 1, while 72, 88 and 96 undergo only one-step monometalation reactions.
TRANSITION STATES IN INTRAMOLECULAR SN2 REACTIONS OF CARBANIONS. THE CLOSURE OF THREE-, FOUR- AND FIVE-MEMBERED RINGS
Benedetti, Fabio,Fabrissin, Silvio,Rusconi, Alessandro,Stirling, Charles J. M.
, p. 233 - 240 (2007/10/02)
The intramolecular displacement of aryl ethyl sulphonium by carbanions stabilised by two sulphonyl groups has been studied.Rates of cyclisation of three-, four- and five-membered rings follow the same trend observed in the analogous displacement of halides.The effects of substituents on the leaving group show that, in the series considered, variations in the extent of bond cleavage to the leaving group are small.
SELECTIVE CLEAVAGE OF THE CARBON-SULPHUR AND CARBON-OXYGEN BONDS IN METHOXYTHIOANISOLES
Testaferri, L.,Tiecco, M.,Tingoli, M.,Chianelli, D.,Maiolo, F.
, p. 2721 - 2724 (2007/10/02)
Selective cleavage of thioether or ether functions in methoxythioanisoles in hexamehtylphosphoramide (HMPA) with sodium gives methoxythiophenols by cleavage of the carbon-sulphur bond.Reactions with sodium isopropanethiolate give instead the thiomethoxyphenols by dealkylation of the methoxy function.When the methoxythioanisoles were treated first with sodium isopropanethiolate and then with sodium complete dealkylation was achieved with formation of mercaptophenols.The present methods have considerable advantages over existing procedures for the synthesis of methoxythiophenols, thiomethoxyphenols and mercaptophenols.The mechanistic implications of the reactions investigated are also discussed.
