20898-85-5Relevant academic research and scientific papers
New Types of Very Efficient Photolabile Protecting Groups Based upon the [2-(2-Nitrophenyl)propoxy]carbonyl (NPPOC) Moiety
Buehler, Sigrid,Lagoja, Irene,Giegrich, Heiner,Stengele, Klaus-Peter,Pfleiderer, Wolfgang
, p. 620 - 659 (2007/10/03)
Based upon the photolabile [2-(2-nitrophenyl)propoxy]carbonyl group (NPPOC), a large number of modified 2-(2-nitrophenyl)propanol derivatives substituted at the phenyl ring (see 23-34 and 57-76) as well as at the side-chain (see 85-92 and 95-98) were synthesized to improve the photoreactivity of this new type of photolabile entity. The phenyl moiety was also exchanged by the naphthalenyl group (see 102, 103, 105, 108, 110, 113, and 114), the thienyl substituent (see 115, 117, 118, and 120), and the benzothienyl substituent (see 121). The 2-(2-nitroaryl- and heteroaryl) propanols were converted with diphosgene into the corresponding carbonochloridates, which reacted subsequently with thymidine to the thymidine 5′-(protected carbonates) 123-178 as the main reaction products. In several cases, the corresponding 3′-carbonates and 3′,5′ -dicarbonates 179-212 were also isolated and characterized. Photolysis studies under standardized conditions (see Table) indicated that the rate of photocleavage varies in a broad range depending on the substituents. So far, the thymidine 5′-[2-(5-halo-2-nitrophenyl)propyl carbonates] 127-129, 5′-[2-(nitro[1,1′-biphenyl]3-yl)propyl carbonates] 136-139, 5′-{2-[2-nitro-5-(thianthren-1-yl)phenyl]propyl carbonate} (140), 5′-[2-(5-naphthalenyl-2-nitrophenyl)propyl carbonates] 141 and 142, and 5′-[2-(2-nitro-5-thienylphenyl)propyl carbonates] 143 and 144 showed the best properties regarding fast and uniform deprotection. Since the nucleobases of 213-215 do not influence the photocleavage features, in general, the new type of photolabile building blocks allows in form of their 3′ -phosphoramidites the photolithographic formation of high-quality biochips.
Studies on the reductively triggered release of heterocyclic and steroid drugs from 5-nitrothien-2-ylmethyl prodrugs
Ferrer, Sandra,Naughton, Declan P.,Threadgill, Michael D.
, p. 3437 - 3444 (2007/10/03)
Hypoxia (inadequate concentrations of dioxygen in tissues) is present in several disease states, including cancer and rheumatoid arthritis. Prodrug systems, which after bioreduction, selectively release active drugs in these tissues may be important in therapy. The 5-nitrothien-2-ylmethyl ester of aspirin was synthesised by treatment of 5-nitrothiophene-2-methanol with 2-acetoxybenzoyl chloride, whereas that of prednisolone hemisuccinate was prepared by reaction of prednisolone with 5-nitrothien-2-ylmethyl pentafluorophenyl butanedioate. In chemical model systems, both of these ester-linked potential prodrugs suffered hydrolysis, rather than reductively triggered release of the corresponding drug. 1-(5-Nitrothien-2-ylmethoxy)isoquinolines released the corresponding isoquinolin-1-ones (potent inhibitors of poly(ADP-ribose)polymerase) rapidly upon reduction of the nitro group with sodium borohydride/palladium, showing that these may be useful as reductively triggered prodrugs. In approaches to N-linked potential prodrugs, isoquinolin-1-one and nifedipine (a 1,4-dihydropyridine Ca2+ channel antagonist) were alkylated at nitrogen by 2-chloromethylthiophene but the corresponding 5-nitrothien-2-ylmethyl derivatives were synthetically inaccessible.
