15031-78-4Relevant articles and documents
Proton NMR and IR study of self-association in pyridylalkanols: Open or cyclic dimers? Higher polymers?
Lomas, John S.,Adenier, Alain,Cordier, Christine
, p. 295 - 307 (2007/10/03)
1H NMR measurements indicate that (X-pyridyl)alkanols of the general formula (C5H4N)(CH2)nOH, where n = 1, 2 or 3, self-associate as open dimers, cyclic dimers, trimers and tetramers, with considerable variations depending on the position of the alkyl chain and its length. (X-Pyridyl)propan-2-ols behave like the corresponding pyridylmethanols with, however, somewhat lower association constants. The IR spectra of 3-(X-pyridyl)-2,2,4,4-tetramethylpentan-3-ols (X = 3 or 4) in carbon tetrachloride suggest weak association, while the 2-pyridyl derivative occurs mainly as the intramolecularly hydrogen-bonded rotamer. The OH NMR shifts for the 3- and 4-pyridyl derivatives in benzene are concentration-dependent, but neither the equilibrium constants nor the degree of association can be evaluated. Benzyl alcohol in benzene associates as an open dimer and a cyclic tetramer, as does 2phenylpropan-2-ol, only more weakly. Rotation barriers for 3-(X-pyridyl)-2,2,4,4-tetramethylpentan-3-ols (X = 2, 3 or 4) in DMSO or nitrobenzene are 20-21 kcal mol-1. Copyright
Kinetics of the self-assembly of α-cyclodextrin [2]pseudorotaxanes with 1,12-bis(4-(α-alkyl-α-methylmethanol)pyridinium)dodecane dications in aqueous solution
Smith, A. Catherine,Macartney, Donal H.
, p. 9243 - 9251 (2007/10/03)
The kinetics and thermodynamics of the self-assembly of a series of [2]pseudorotaxanes comprised of α-cyclodextrin (α-CD) and racemic 1,12- bis(4-(α-alkyl-α-methylmethanol)pyridinium)dodecane dications (L(CH2)12L2+) in aqueous solutions have been investigated using 1H NMR spectroscopy. The mechanism of assembly involves inclusion of the α-methyl- α-alkylmethanol substituent groups (-C(CH3)(OH)R, where R = Me, Et, Pr, Bu, allyl, and 4-butenyl) by α-CD, followed by a rate-determining passage of the cyclodextrin over the pyridinium group onto the dodecamethylene chain. Dicationic threads containing end groups with R = Ph or i-Pr or where L = 4- (α,α-diethylmethanol)-pyridinium did not form α-cyclodextrin pseudorotaxanes, even after prolonged heating. The trends in the rate and activation parameters may be related to the size, shape, and hydrophobicity of the alkyl substituents and are compared with several other systems from the literature. An increase in the length and hydrophobicity of the alkyl group increases the strength of end group inclusion and decreases the rate of threading. In addition, the presence of unsaturation in the alkyl substituent (allyl vs propyl and 4-butenyl vs butyl) results in an increase in the threading rate constant.
3- and 4-pyridylalkyl adamantanecarboxylates: Inhibitors of human cytochrome P450(17α) (17α-hydroxylase/C17,20-lyase). Potential nonsteroidal agents for the treatment of prostatic cancer
Chan, Ferdinand C. Y.,Potter, Gerard A.,Barrie, S. Elaine,Haynes, Benjamin P.,Rowlands, Martin G.,Houghton, John,Jarman, Michael
, p. 3319 - 3323 (2007/10/03)
Various 3- and 4-pyridylalkyl 1-adamantanecarboxylates have been synthesized and tested for inhibitory activity toward the 17α-hydroxylase and C17,20-lyase activities of human testicular cytochrome P450(17α). The 4-pyridylalkyl esters were much more inhibitory than their 3- pyridylalkyl counterparts. The most potent was (S)-1-(4-pyridyl)ethyl 1- adamantanecarboxylate (3b; IC50 for lyase, 1.8 nM), whereas the (R)- enantiomer 3a was much less inhibitory (IC50 74 nM). Nearly as potent as 3b was the dimethylated counterpart, the 2-(4-pyridylpropan-2-yl) ester 5 (IC50 2.7 nM), which was also more resistant to degradation by esterases. In contrast to their 4-pyridyl analogs, the enantiomers of the 1-(3- pyridyl)ethyl ester were similarly inhibitory (IC50 for lyase; (R)-isomer 8a 150 nM, (S)-isomer 8b 230 nM). Amides corresponding to the 4- pyridylmethyl ester 1 and the (S)-1-(4-pyridyl)ethyl ester 3b, respectively 11 and 15b, were much less inhibitory than their ester counterparts. On the basis of a combination of inhibitory potency and resistance to esterases, the ester 5 was the best candidate for further development as a potential nonsteroidal inhibitor of cytochrome P450(17α) for the treatment of prostate cancer.
