347368-07-4Relevant articles and documents
A segmented flow platform for on-demand medicinal chemistry and compound synthesis in oscillating droplets
Hwang, Ye-Jin,Coley, Connor W.,Abolhasani, Milad,Marzinzik, Andreas L.,Koch, Guido,Spanka, Carsten,Lehmann, Hansjoerg,Jensen, Klavs F.
, p. 6649 - 6652 (2017/07/10)
We report an automated flow chemistry platform that can efficiently perform a wide range of chemistries, including single/multi-phase and single/multi-step, with a reaction volume of just 14 μL. The breadth of compatible chemistries is successfully demonstrated and the desired products are characterized, isolated, and collected online by preparative HPLC/MS/ELSD.
A Heterogeneous Niobium(V) Oxide Catalyst for the Direct Amidation of Esters
Ali, Md. Ayub,Siddiki, S. M. A. Hakim,Kon, Kenichi,Shimizu, Ken-Ichi
, p. 2705 - 2710 (2015/09/15)
This study reports the first example of a heterogeneous catalytic system for the direct amidation of various esters with amines. Of 25 types of catalyst, Nb2O5 shows the highest activity in the amidation of methyl benzoate with aniline. Nb2O5 gives high yields in the amidation of various esters and amines under solvent-free conditions, is reusable, and shows higher turnover numbers than previously reported homogeneous catalysts such as La(OTf)3. IR spectroscopic studies of ethyl acetate adsorbed on the catalysts show a strong acid-base interaction between the Nb5+ Lewis acid site and carbonyl oxygen, which can result in high reactivity of the ester with a nucleophile (amine) and, thus, high activity of Nb2O5. Kinetic results show that the activity of Nb2O5 does not markedly decrease with increasing aniline concentration, in contrast to reference catalysts TiO2 and La(OTf)3. The relatively low negative impact of basic molecules on the Lewis acid catalysis of Nb2O5 also enables its high activity.
B(OCH2CF3)3-mediated direct amidation of pharmaceutically relevant building blocks in cyclopentyl methyl ether
Karaluka, Valerija,Lanigan, Rachel M.,Murray, Paul M.,Badland, Matthew,Sheppard, Tom D.
supporting information, p. 10888 - 10894 (2015/11/17)
The use of B(OCH2CF3)3 for mediating direct amidation reactions of a wide range of pharmaceutically relevant carboxylic acids and amines is described, including numerous heterocycle-containing examples. An initial screen of solvents for the direct amidation reaction suggested that cyclopentyl methyl ether, a solvent with a very good safety profile suitable for use over a wide temperature range, was an excellent replacement for the previously used solvent acetonitrile. Under these conditions amides could be prepared from 18 of the 21 carboxylic acids and 18 of the 21 amines examined. Further optimisation of one of the low yielding amidation reactions (36% yield) via a design of experiments approach enabled an 84% yield of the amide to be obtained.
