347370-91-6Relevant academic research and scientific papers
Nickel-Catalyzed Reductive Cross-Coupling of N-Acyl and N-Sulfonyl Benzotriazoles with Diverse Nitro Compounds: Rapid Access to Amides and Sulfonamides
Qu, Erdong,Li, Shangzhang,Bai, Jin,Zheng, Yan,Li, Wanfang
supporting information, p. 58 - 63 (2021/12/27)
Herein we report a Ni-catalyzed reductive transamidation of conveniently available N-acyl benzotriazoles with alkyl, alkenyl, and aryl nitro compounds, which afforded various amides with good yields and a broad substrate scope. The same catalytic reaction conditions were also applicable for N-sulfonyl benzotriazoles, which could undergo smooth reductive coupling with nitroarenes and nitroalkanes to afford the corresponding sulfonamides.
Concise Modular Synthesis and NMR Structural Determination of Gallium Mycobactin T
Chan, Kiat Hwa,Groves, John T.
, p. 15453 - 15468 (2021/11/16)
A modular synthesis of mycobactin T and its N-acetyl analogue is reported in a route that facilitates permutation of the lipid tails. A key feature is the generation of N(α)-Cbz-N(?)-benzyloxy-N(?)-Boc-lysine (A4) with methyl(trifluoromethyl)dioxirane in 59% yield. Selective hydroxamate N-acylation was achieved with acyl fluorides, enabling installation of lipids tails in the final step. O-Benzyl-dehydrocobactin T (B4) was prepared by modifying a known five-step sequence with an overall yield of 49%. 2-Hydroxyphenyl-4-carboxyloxazoline (C3) was prepared from 2-hydroxybenzoic acid and l-serine methyl ester in three steps with an overall yield of 55%. Ester coupling of A4 and B4 with EDCI afforded MbI-1 in 73% yield. Catalytic hydrogenation with Pd/BaSO4 and 50 psi of H2 simultaneously effected alkene reduction and debenzylation to afford MbI-2 in 96% yield. Fragment C3 was converted into acyl fluoride C4, which coupled with MbI-2 to afford MbI-3 in 51% yield. Finally, Boc-removal with HCl/EtOAc and treatment of the resultant hydroxylamine with stearyl fluoride furnished mycobactin T in 65% yield. Overall, the yield is 4% over 14 steps. The gallium mycobactin T-N-acetyl derivative (GaMbT-NAc) structure was determined by 1H NMR. The structure shows an octahedral Ga and two internal hydrogen bonds between peptidic N-Hs and two of the oxygen atoms coordinating Ga.
An efficient one-pot synthesis of: N, N ′-disubstituted ureas and carbamates from N -acylbenzotriazoles
Singh, Anoop S.,Kumar, Dhananjay,Mishra, Nidhi,Tiwari, Vinod K.
, p. 84512 - 84522 (2016/10/12)
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 in different solvents gives different products i.e. carbamates in alcohols and N,N′-disubstituted symmetrical urea in THF.
Synthesis of benzoxazines, quinazolines and 4H-benzo[e][1,3]thiazine by ANRORC rearrangements of 1,2,4-oxadiazoles
Draghici, Bogdan,El-Gendy, Bahaa El-Dien M.,Katritzky, Alan R.
supporting information; experimental part, p. 547 - 550 (2012/04/04)
1,2,4-Oxadiazoles undergo ANRORC (addition of nucleophile, ring-opening and ring-closure) rearrangements upon reaction with excess of n-butyllithium to give benzoxazines, benzothiazines, and quinazolines in good yields under mild conditions. Georg Thieme Verlag Stuttgart · New York.
Direct synthesis of esters and amides from unprotected hydroxyaromatic and -aliphatic carboxylic acids
Katritzky, Alan R.,Singh, Sanjay K.,Cai, Chunming,Bobrov, Sergey
, p. 3364 - 3374 (2007/10/03)
A facile method for the activation of hydroxy-substituted carboxylic acids using benzotriazole chemistry without prior protection of the hydroxy substituents is presented. The N-acylbenzotriazole intermediates 2a-g, 6a-d, and 9a-c have been used for high-yielding synthesis of both aliphatic (3a-1) and aromatic (7a-h, 10a-f) hydroxy carboxamides. High yields of aromatic hydroxy esters 12a-h and 13a-i were obtained using either neat alcohols in neutral microwave conditions or nucleophilic alkoxides and the intermediate N-(arylacyl)benzotriazoles. Moderate yields were obtained in the case of aliphatic hydroxy esters 11a,b and thiolesters 11e-g from the intermediates 2a-c.
New 5-substituted-1-(2-hydroxybenzoyl)-benzotriazoles, potassium channel activators. IV.
Biagi,Giorgi,Livi,Scartoni,Barili,Calderone,Martinotti
, p. 827 - 834 (2007/10/03)
This paper reports the synthesis of a series of new 5-substituted-1-(2-hydroxybenzoyl)-benzotriazoles, which have been tested for their activity as possible activators of potassium channels. In rat aortic rings, the 'opened' derivatives 1a-f, intermediates of synthesis, showed vasorelaxing properties, with appreciable values of potency. However, the most remarkable effects were recorded for the 2-hydroxybenzoylbenzotriazoles 3a-f, which showed full vasorelaxing efficacy and high potency values. The introduction of a 2-hydroxybenzyl substituent in the 1 position of the benzotriazole ring (compound 7) strongly decreased the activity, showing the importance of the electron-acceptor carbonyl function. The best compound, 3b, was further investigated, in order to evaluate the possible mechanism of action involved in the vasodilator activity. In the vascular model, different potassium channel blockers inhibited the effects of the compound, and an increase of the levels of membrane depolarisation induced a significant reduction of the recorded responses. Compound 3b was also tested in a model of isolated rat heart, retroperfused through the aorta and submitted to a global ischemia/reperfusion cycle. In such an experimental condition, 3b showed an interesting cardioprotective activity. All the above observations are in agreement with the hypothesis of a mechanism linked to the activation of potassium channels.
