FeCl3 · 6H2O-Catalyzed Acceleration of the Acylation of Sodium Azide withN-Acylbenzotriazoles
摘要:
[image omitted] Catalyzed by ferric chloride hexahydrate (FeCl3 center dot 6H2O), the acylation of sodium azide with N-acylbenzotriazoles was greatly accelerated in a mixed solvent of acetone and water. Thus, good to excellent yields of a variety of acyl azides were obtained at room temperature in a short time. Furthermore, because of the complete conversion of N-acylbenzotriazoles and the easy removal of the by-product, purification by column chromatography was no longer required, which made the protocol suitable for large-scale preparation.
N-Acylbenzotriazoles as Proficient Substrates for an Easy Access to Ureas, Acylureas, Carbamates, and Thiocarbamates via Curtius Rearrangement Using Diphenylphosphoryl Azide (DPPA) as Azide Donor
作者:Vinod K. Tiwari、Mangal S. Yadav、Sumt K. Singh、Anand K. Agrahari、Anoop S. Singh
DOI:10.1055/a-1399-3823
日期:2021.7
found to be a good alternative to trimethylsilyl azide and sodium azide for the azide donor in Curtius degradation. The high reaction yields, one-pot and metal-free conditions, straightforward nature, easy handling, use of readily available reagents, and in many cases avoidance of column chromatography are the notable features of the devised protocol.
An efficient one-pot synthesis of N,N′-disubstituted ureas and carbamates from N-acylbenzotriazoles
作者:Anoop S. Singh、Dhananjay Kumar、Nidhi Mishra、Vinod K. Tiwari
DOI:10.1039/c6ra14131e
日期:——
A facile and high-yielding one-pot synthesis of carbamates and N,N'-disubstituted symmetrical ureas from N-acylbenzotriazoles has been devised. It is believed that, the intermediate acyl-azide undergo Curtius rearrangement and under different...
Facile Syntheses of Oxazolines and Thiazolines with <i>N</i>-Acylbenzotriazoles under Microwave Irradiation
作者:Alan R. Katritzky、Chunming Cai、Kazuyuki Suzuki、Sandeep K. Singh
DOI:10.1021/jo0355092
日期:2004.2.1
Microwave reactions of 2-amino-2-methyl-1-propanol (2) or 2-aminoethanethiol hydrochloride (4) with readily available N-acylbenzotriazoles 1a−j in the presence of SOCl2 produced 2-substituted 2-oxazolines 3a−j in 84−98% yields and 2-substituted thiazolines 5a−i in 85−97% yields, respectively. With use of this method chiral oxazoline 6, bisoxazoline 7, bisthiazoline 8, and 5,6-dihydro-4H-1,3-oxazines
在SOCl 2的存在下,2-氨基-2-甲基-1-丙醇(2)或2-氨基乙硫醇盐酸盐(4)与易于获得的N-酰基苯并三唑1a - j的微波反应产生了2-取代的2-恶唑啉3a - j分别以84-98%的产率和2-取代的噻唑啉5a - i的产率为85-97%。使用该方法时,手性恶唑啉6,双恶唑啉7,双噻唑啉8和5,6-二氢-4 H -1,3-恶嗪9或10还制备了82-96%的产率。这些结果证明了N-酰基苯并三唑在温和条件下和微波辐射下反应时间短的情况下在恶唑啉和噻唑啉制备中的新应用。
Synthesis and Structure−Activity Relationship Studies of Cytotoxic Ester and Ether Anhydrovinblastine Derivatives
作者:Han-Kun Zhang、Yong Shao、Hong Ding、Li-Hong Hu
DOI:10.1021/np800284h
日期:2008.10.24
activities against human non-small-cell lung cancer (A549) and cervical epithelial adenocarcinoma (HeLa) cell lines. Ester anhydrovinblastine derivatives exhibited potent cytotoxicity, whereas the ether analogues were much less active. The size of the introduced substituents was the foremost factor in determining the resultant cytotoxic activity. Compound 12b showed a similar cytotoxic potency to the
Samarium diiodide promoted formation of 1,2-diketones and 1-acylamido-2-substituted benzimidazoles from N-acylbenzotriazoles
作者:Xiaoxia Wang、Yongmin Zhang
DOI:10.1016/s0040-4020(03)00575-1
日期:2003.6
N-Acylbenzotriazoles, when treated with samarium diiodide in THF, undergo self-coupling reaction to afford 1,2-diketones in good to excellent yields; while when treated with samarium diiodide in CH3CN, they undergo ring-opening reaction to afford 1-acylamido-2-alkyl (or aryl) benzimidazoles in reasonable to good yields. A plausible mechanism was suggested.