A fast and highly efficient one-pot synthesis of novel isoxazolyl pyrido[2,3-b][1,4]oxazin-2(3H)-ones via Smiles rearrangement using task-specific ionic liquid [HMIm]BF4 as green solvent was written by Reddy, Modugu Nagi;Kumar, Pittala Praveen;Rajanarendar, Eligeti. And the article was included in Green Chemistry Letters and Reviews in 2017.Safety of 2-Chloro-5-fluoropyridin-3-ol This article mentions the following:
A facile and convenient procedure for the synthesis of isoxazolyl pyrido[2,3-b][1,4]oxazin-2(3H)-ones I (R = 5-methylisoxazol-3-yl, 3,5-dimethylisoxazol-4-yl, 3-methyl-5-styrylisoxazol-4-yl; R1 = H, Me; X = H, F, Cl, Br) via Smiles rearrangement from isoxazol amines, chloroacetyl chlorides and 2-chloro-3-hydroxypyridines using [HMIm]BF4 as task-specific ionic liquid has been described. The protocol proves to be efficient and environmentally benign in terms of high yields, eco-friendly solvent, ease of recovery, and reusability of reaction medium. In the experiment, the researchers used many compounds, for example, 2-Chloro-5-fluoropyridin-3-ol (cas: 884494-35-3Safety of 2-Chloro-5-fluoropyridin-3-ol).
2-Chloro-5-fluoropyridin-3-ol (cas: 884494-35-3) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Safety of 2-Chloro-5-fluoropyridin-3-ol