The synthesis process of 2-mercapto-5-methoxyimidazo[4,5-b]pyridine, a crucial intermediate of tenatoprazole which is a new proton pump inhibitor, was studied.2,6-Dichloropyridine as raw material was nitrated by nitri...The synthesis process of 2-mercapto-5-methoxyimidazo[4,5-b]pyridine, a crucial intermediate of tenatoprazole which is a new proton pump inhibitor, was studied.2,6-Dichloropyridine as raw material was nitrated by nitric acid/sulfuric acid, and after amination 2-amino-3-nitro-6-chloropyridine was obtained.It then reacted with sodium methoxide to give 2-amino-3-nitro-6-methoxypyridine and the intermediate was reduced by H2 with Raney Ni as catalyst to give 2,3-diamino-6-methoxypyridine.Finally cyclization was finished with carbon bisulfide to give the title compound.The optimal reaction conditions and yield(temperature, time, molar yield) were as follows: nitration,110℃, 8 h, 79.3%; amination, room temperature, 10 h, 87.6%; methoxylation,65℃, 30min, 98.7%; reduction,70℃, 3 h; cyclization, reflux, 4 h, 72.4% (two steps).The melting point of the title compound was the same as that reported in literature, and its structure was confirmed by 1H NMR.展开更多
Titanium dioxide(TiO_(2))has been limited in photocatalysis due to its wide band gap(3.2 eV)and limited absorption in the ultraviolet range.Therefore,organic components have been introduced to hybrid with TiO_(2) for ...Titanium dioxide(TiO_(2))has been limited in photocatalysis due to its wide band gap(3.2 eV)and limited absorption in the ultraviolet range.Therefore,organic components have been introduced to hybrid with TiO_(2) for enhanced photocatalytic efficiency under visible light.Here,we report that benzo[1,2-b:4,5-b']dithiophene polymer was an ideal organic material for the preparation of a hybrid material with TiO_(2).The energy band gap of the resulting hybrid material decreased to 2.9 eV and the photocatalytic hydrogen production performance reached 745.0μmol g^(-1) h^(-1) under visible light irradiation.Meanwhile,the material still maintained the stability of hydrogen production performance after 40 h of photocatalytic cycles.The analysis of the transient current response and electrochemical impedance revealed that the main reasons for the enhanced water splitting of the hybrid materials were the faster separation of electron hole pairs and the lower recombination of photocarrier ions.Our findings suggest that polythiophene is a promising organic material for exploring hybrid materials with enhanced photocatalytic hydrogen production.展开更多
文摘The synthesis process of 2-mercapto-5-methoxyimidazo[4,5-b]pyridine, a crucial intermediate of tenatoprazole which is a new proton pump inhibitor, was studied.2,6-Dichloropyridine as raw material was nitrated by nitric acid/sulfuric acid, and after amination 2-amino-3-nitro-6-chloropyridine was obtained.It then reacted with sodium methoxide to give 2-amino-3-nitro-6-methoxypyridine and the intermediate was reduced by H2 with Raney Ni as catalyst to give 2,3-diamino-6-methoxypyridine.Finally cyclization was finished with carbon bisulfide to give the title compound.The optimal reaction conditions and yield(temperature, time, molar yield) were as follows: nitration,110℃, 8 h, 79.3%; amination, room temperature, 10 h, 87.6%; methoxylation,65℃, 30min, 98.7%; reduction,70℃, 3 h; cyclization, reflux, 4 h, 72.4% (two steps).The melting point of the title compound was the same as that reported in literature, and its structure was confirmed by 1H NMR.
基金financial support from Hainan Province Natural Science Foundation of China (No. 219QN151)the National Natural Science Foundation of China (21801052)+1 种基金Hainan University Start-up Fund (No. KYQD(ZR)1852)the Construction Program of Research Platform in Hainan University (No. ZY2019HN09)。
文摘Titanium dioxide(TiO_(2))has been limited in photocatalysis due to its wide band gap(3.2 eV)and limited absorption in the ultraviolet range.Therefore,organic components have been introduced to hybrid with TiO_(2) for enhanced photocatalytic efficiency under visible light.Here,we report that benzo[1,2-b:4,5-b']dithiophene polymer was an ideal organic material for the preparation of a hybrid material with TiO_(2).The energy band gap of the resulting hybrid material decreased to 2.9 eV and the photocatalytic hydrogen production performance reached 745.0μmol g^(-1) h^(-1) under visible light irradiation.Meanwhile,the material still maintained the stability of hydrogen production performance after 40 h of photocatalytic cycles.The analysis of the transient current response and electrochemical impedance revealed that the main reasons for the enhanced water splitting of the hybrid materials were the faster separation of electron hole pairs and the lower recombination of photocarrier ions.Our findings suggest that polythiophene is a promising organic material for exploring hybrid materials with enhanced photocatalytic hydrogen production.
