Application of NMI-TfCl-mediated amide bond formation in the synthesis of biologically relevant oxadiazole derivatives employing less basic (hetero)aryl amines

NMI-SO2Cl2-Mediated Amide Bond Formation: Facile Synthesis of Some Dihydrotriazolopyrimidine Amide Derivatives as Potential Anti-Inflammatory and Anti-Tubercular Agents

“…Finally, the nucleophilic attack of amines 5a-i takes place on this intermediate, leading to the formation of the corresponding amides 6. The plausible mechanism for the formation of the different amides has been proposed in Scheme 5 by taking acid 4a as an example [28]. During our initial optimization studies (Table 1, entry 7), we obtained the expected product in a lesser yield when NMI was replaced by triethylamine (TEA) as the base.…”

“…Th method avoids the use of coupling agents, which need further processing to remove th side products associated with these reagents. The desired amide product 6de was ob tained in a 75% isolated yield when the reaction was carried out for 5 h. The plausible mechanism for the formation of the different amides has been pro posed in Scheme 5 by taking acid 4a as an example [28]. During our initial optimizatio studies (Table 1, entry 7), we obtained the expected product in a lesser yield when NM was replaced by triethylamine (TEA) as the base.…”

“…Considering the biological importance of 1,2,4-triazoles, dihydropyrimidines and amides, the development of an efficient amide formation methodology to access these otherwise challenging amides is of immense potential. In view of these aforementioned observations and as a continuation of our research in developing biologically active substances [27][28][29], we were interested in synthesizing some novel dihydrotriazolopyrimidine derivatives containing amide functionality. Accordingly, we herein report the synthesis of a series of dihydrotriazolopyrimidine derivatives linked to amides by utilizing the N-methylimidazole (NMI) and sulfuryl chloride (SO 2 Cl 2 )-mediated amide bond formation reaction.…”

Evaluation of Anti-Inflammatory and Anti-Tubercular Activity of 4-Methyl-7-Substituted Coumarin Hybrids and Their Structure Activity Relationships

“…This is a well-established approach leading to more potent drugs and could be beneficial for the treatment of various diseases in the near future [ 30 , 31 ]. In continuation of our ongoing research work on the synthesis and pharmacological screening of biologically active molecules [ 32 , 33 ], we directed our attention toward evaluating the anti-inflammatory and anti-tubercular properties of some 4-methyl-7-substituted coumarin derivatives. The synthesis of these target compounds was previously reported by our research group [ 34 , 35 , 36 ].…”