A facile, catalyst-free mechano-synthesis of quinoxalines and their in-vitro antibacterial activity study was written by Bhutia, Zigmee T.;Prasannakumar, Geethika;Das, Avijit;Biswas, Malabika;Chatterjee, Amrita;Banerjee, Mainak. And the article was included in ChemistrySelect in 2017.SDS of cas: 322-46-3 This article mentions the following:
A catalyst-free, greener and highly efficient method for the synthesis of quinoxaline derivatives I (R1 = Ph, Me, H, etc.; R2 = H, Me; R3 = H, Me, Cl, NO2; R4 = H, Me; X = CH, N) involving simple liquid assisted hand-grinding (LAG) in a mortar and pestle was developed. The mechanochem. agitation under LAG was sufficient enough for the smooth condensation of both aromatic and heteroaromatic 1,2-diamines with a variety of 1,2-dicarbonyl compounds to afford the corresponding quinoxalines in high yields. Several of these quinoxaline derivatives inhibited the growth of Mycobacterium smegmatis in moderate to good effect. Simple substitution in the quinoxaline ring was found to be more effective in antibacterial agents than bulky substitution. In particular, pyrido[2,3-b]pyrazines I (R1 = H, CH3; R2 = R4 = H; R3 = H, Br; X = N) showed better activity than others. Overall, the key advantages of this method were simplicity of operation, catalyst-free condition, solvent-less synthesis, low E-factor, cleaner reaction profile, devoid of work-up step, easy purification and shorter reaction times, and the new series of pyrido[2,3-b]pyrazines were good antibacterial agents against M. smegmatis. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3SDS of cas: 322-46-3).
Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine has the elements of symmetry for the point group D2h. It has three mutually perpendicular two-fold axes. It also has three mutually perpendicular planes of symmetry. As a result, pyrazine also has a centre of symmetry. Pyrazine-based skeletons were incorporated into agents targeting a range of ailments. Many derivatives were synthesized and evaluated as potential cancer treatments.SDS of cas: 322-46-3