157014-41-0Relevant articles and documents
FURAZANOBENZIMIDAZOLES AS PRODRUGS TO TREAT NEOPLASTIC OR AUTOIMMUNE DISEASES
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Page/Page column 29; 30, (2011/02/24)
A compound of formula (II) wherein (a) represents a divalent benzene residue which is unsubstituted or substituted by one or two additional substituents independently selected from lower alkyl, halo-lower alkyl, hydroxy-lower alkyl, lower alkoxy-lower alkyl, acyloxy-lower alkyl, phenyl, hydroxy, lower alkoxy, hydroxy-lower alkoxy, lower alkoxy-lower alkoxy, phenyl-lower alkoxy, lower alkylcarbonyloxy, amino, mono(lower alkyl)amino, di(lower alkyl)amino, mono(lower alkenyl)amino, di(lower alkenyl)amino, lower alkoxycarbonylamino, lower alkylcarbonylamino, substituted amino wherein the two substituents on nitrogen form together with the nitrogen heterocyclyl, lower alkylcarbonyl, carboxy, lower 15 alkoxycarbonyl, cyano, halogen, and nitro; or wherein two adjacent substituents can be methylenedioxy; or a divalent pyridine residue (Z = N) which is unsubstituted or substituted additionally by lower alkyl, lower alkoxy, lower alkoxy-lower alkoxy,amino, optionally substituted by one or two substituents selected from lower alkyl, lower alkenyl and alkylcarbonyl, halo-20 lower alkyl, lower alkoxy-lower alkyl, or halogen; R1 represents hydrogen, lower alkylcarbonyl, hydroxy-lower alkylor cyano-loweralkyl; and R2 represents a group selected from: (b), (c) and (d); or pharmaceutically acceptable salts thereof.
New photoactivated protecting groups. 6. p-Hydroxyphenacyl: A phototrigger for chemical and biochemical probes
Park, Chan-Ho,Givens, Richard S.
, p. 2453 - 2463 (2007/10/03)
p-Hydroxyphenacyl, a new photoactive, aqueous soluble protecting group is proposed as a second generation α-keto 'cage' reagent, a phototrigger for the efficient, rapid release of bioactive phosphates, e.g., inorganic phosphate (P(i)) and ATP (Givens, R.S.; Park, C.-H. Tetrahedron Lett. 1996, 37, 6259-6262). p-Hydroxyphenacyl esters 6c and 7 trigger the release of P(i) and ATP when irradiated at wavelengths between 300-350 nm also yielding p-hydroxyphenylacetic acid (8) from the rearrangement of the intermediate α-keto carbocation or its equivalent. In contrast, unsubstituted and m-substituted phenacyl esters yield only photoreduction and radical coupling products and none of the rearrangement product. Quantum efficiencies of 0.38 ± 0.04 were measured for the disappearance of the p-hydroxyphenacyl phosphate esters 6c and 7; the appearance efficiencies for 8 and ATP were 0.30 ± 0.03. Rates of release of ~107 s-1 or better are observed for these esters with only minor variations in efficiencies and rate constants between these two examples of the p-hydroxyphenacyl phototrigger. Just as was found for the desyl 'cage' series reported earlier (Givens, R.S.; Athey, P.S.; Kueper, L.W., III; Matuszewski, B.; Xue, J.-y.; Fister, T.J. Am. Chem. Soc. 1993, 115, 6001-6010), the p-hydroxyphenacyl derivatives react via their triplet states. Amino substituents, i.e., p-amino-, p-acetamido-, and p-(carbomethoxyamino)phenacyl phosphates 6f-h, were also investigated, but these analogues proved to be inferior as phototriggers when compared with p-hydroxyphenacyl.
