Syntheses and Properties of 1-Methyl-3-phenylaminobenzimidazolium Salts, Models of DNA Adducts of N7-Arylaminodeoxyguanosinium Salt
摘要:
When arylaminating carcinogens are administered to cells, they mainly generate the C8-arylamino-2'-deoxyguanosine adduct in DNA. A mechanism for this was proposed in which N7-arylaminated 2'-deoxyguanosine acts as an intermediate; however, it remained unclear whether this is actually the case. To elucidate the mechanisms involved in the generation of this adduct, a series of 5-substituted 1-methylbenzimidazole derivatives were used as models of the imidazole moiety of 2'-deoxyguanosine. Syntheses of a series of 5-substituted (CH3, H, F, CF3, or NO2) 1-methyl-3-phenylaminobenzimidazolium salts (7) and their related compounds were carried out, and the chemical characteristics of these products were examined. Keating compound 7 at 80 degreesC for 48 h in H2O/MeOH provided 5-substituted 1-methyl-2-oxo-2,3-dihydrobenzimidazoles but only when this compound contained a CF3 or NO2 substituent. Compound 7 decomposed in alkaline media, and its rate of decomposition increased when this compound had a stronger electron-withdrawing substituent. The product obtained under these conditions was 4-substituted N-1-methyl-2-phenylazoaniline. On the other hand, when 1-methyl-3-(4-nitrophenylamino)benzimidazolium salt was treated under the same conditions as described above, it generated, a demethylated product, 1-(4-nitrophenylamino)benzimidazole, when heated in H2O/MeOH and N-1-formyl-N-1-methyl-2-phenylazoaniline when treated in alkaline media. When the chemical characteristics of 3-phenylamino and 3-amino groups were compared using 3-substituted 1-methyl-5-(trifluoromethyl)benzimidazole the 3-phenylamino derivative was found to be more reactive.
Syntheses and Properties of 1-Methyl-3-phenylaminobenzimidazolium Salts, Models of DNA Adducts of N7-Arylaminodeoxyguanosinium Salt
摘要:
When arylaminating carcinogens are administered to cells, they mainly generate the C8-arylamino-2'-deoxyguanosine adduct in DNA. A mechanism for this was proposed in which N7-arylaminated 2'-deoxyguanosine acts as an intermediate; however, it remained unclear whether this is actually the case. To elucidate the mechanisms involved in the generation of this adduct, a series of 5-substituted 1-methylbenzimidazole derivatives were used as models of the imidazole moiety of 2'-deoxyguanosine. Syntheses of a series of 5-substituted (CH3, H, F, CF3, or NO2) 1-methyl-3-phenylaminobenzimidazolium salts (7) and their related compounds were carried out, and the chemical characteristics of these products were examined. Keating compound 7 at 80 degreesC for 48 h in H2O/MeOH provided 5-substituted 1-methyl-2-oxo-2,3-dihydrobenzimidazoles but only when this compound contained a CF3 or NO2 substituent. Compound 7 decomposed in alkaline media, and its rate of decomposition increased when this compound had a stronger electron-withdrawing substituent. The product obtained under these conditions was 4-substituted N-1-methyl-2-phenylazoaniline. On the other hand, when 1-methyl-3-(4-nitrophenylamino)benzimidazolium salt was treated under the same conditions as described above, it generated, a demethylated product, 1-(4-nitrophenylamino)benzimidazole, when heated in H2O/MeOH and N-1-formyl-N-1-methyl-2-phenylazoaniline when treated in alkaline media. When the chemical characteristics of 3-phenylamino and 3-amino groups were compared using 3-substituted 1-methyl-5-(trifluoromethyl)benzimidazole the 3-phenylamino derivative was found to be more reactive.
Cu(II)-catalyzed aerobic oxidative amidation of azoarenes with amides
作者:Gang Li、Xiaoting Chen、Xulu Lv、Chunqi Jia、Panpan Gao、Ya Wang、Suling Yang
DOI:10.1007/s11426-017-9175-2
日期:2018.6
dehydrogenative amidation of azoarene using air as the terminal oxidant was developed. Various amides, such as arylamides, alkylamides, lactams, and imides, are all effective amidation reagents and provide the desired products in moderate to excellent yields. Notably, good yields can also be obtained on a gram-scale with this amidation reaction. In this protocol of azoarene amidation, the catalyst (Cu(OAc)2)