Catalyst-free synthesis of substituted pyridin-2-yl, quinolin-2-yl, and isoquinolin-1-yl carbamates from the corresponding hetaryl ureas and alcohols was written by Kasatkina, Svetlana O.;Geyl, Kirill K.;Baykov, Sergey V.;Boyarskaya, Irina A.;Boyarskiy, Vadim P.. And the article was included in Organic & Biomolecular Chemistry in 2021.Category: pyridine-derivatives This article mentions the following:
A novel catalyst-free synthesis of N-pyridin-2-yl, N-quinolin-2-yl, and N-isoquinolin-1-yl carbamates utilizes easily accessible N-hetaryl ureas and alcs. The proposed environmentally friendly technique is suitable for the good-to-high yielding synthesis of a wide range of N-pyridin-2-yl or N-quinolin-2-yl substituted carbamates featuring electron-donating and electron-withdrawing groups in the azine rings and containing various primary, secondary, and even tertiary alkyl substituents at the oxygen atom (48-94%; 31 examples). The DFT calculation and exptl. study showed that the reaction proceeds through the intermediate formation of hetaryl isocyanates. The method can be applied to obtain N-isoquinolin-1-yl carbamates, although in lower yields, and Et benzo[h]quinolin-2-yl carbamate has also been successfully synthesized (68%). In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Category: pyridine-derivatives).
3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Category: pyridine-derivatives