4214-79-3Relevant articles and documents
SPECTROSCOPIC INVESTIGATIONS OF PHASE TRANSITION IN 5-CHLORO-2-PYRIDONE
Raghoottama, P. S.,Soundararajan, S.,Ramakrishna, J.
, p. 371 - 384 (1987)
Spectroscopic investigation of 5-chloro-2-pyridone has been carried out in the temperature range 77-300 K.At room temperature the 35Cl NQR spectrum shows a single line at 35.618 MHz, but at 250.7 K two lines appear at 35.850 MHZ and 35.840 MHz respectively indicating the presence of a phase transition.IR, far-IR, laser Raman and dielectric measurements have been carried out to investigate the phase transition further.Low temperature IR studies show splitting of ν(C-Cl), β(N-H) and ν(C=O) bands at Tc.Dielectric measurements show a small, but finite, change in the value of the dielectric constant around Tc.Raman spectra at different temperatures support the existence of a new phase, as shown by the appearance of a new band at 81 cm-1, the frequency of which changes slowly as Tc is approached and which disappears at Tc.The temperature dependence of the NQR frequencies has been analysed using Bayer Kushida and Brown equations to evaluate the torsional frequencies.
Chemoselective Demethylation of Methoxypyridine
Makino, Kosho,Hasegawa, Yumi,Inoue, Takahide,Araki, Koji,Tabata, Hidetsugu,Oshitari, Tetsuta,Ito, Kiyomi,Natsugari, Hideaki,Takahashi, Hideyo
, p. 951 - 954 (2019/05/10)
A chemoselective demethylation method for various methoxypyridine derivatives has been developed. Treatment of 4-methoxypyridine with L-selectride in THF for 2 h at reflux temperature afforded 4-hydroxypyridine in good yield; no reaction to anisole occurred. The utility of our method was demonstrated by the efficient synthesis of the metabolic substances of the antiulcer agent omeprazole. Chemoselective demethylation at the site of 3,5-dimethyl-4-methoxypyridine in the presence of 4-methoxybenzimidazole was achieved.
Convenient chlorination of some special aromatic compounds using N-chlorosuccinimide
Gan, Zongjie,Hu, Bin,Song, Qiao,Xu, Yungen
experimental part, p. 1074 - 1078 (2012/05/04)
Some chlorinated aromatic compounds, including indole, benzofuran, carbazole, pyridine and aniline derivatives, are difficult to obtain through convenient chlorination. We herein report their efficient synthesis through chlorination with N-chlorosuccinimide (NCS). Optimization of the reaction conditions, including the temperature and the choice of solvent, was also investigated. This approach, which is characterized by a facile procedure, comparatively high yields and environmentally friendly features, provides a straightforward and inexpensive route to several chlorinated aromatic compounds. Georg Thieme Verlag Stuttgart · New York.