The author of 《A Visible-Light-Mediated Radical Smiles Rearrangement and its Application to the Synthesis of a Difluoro-Substituted Spirocyclic ORL-1 Antagonist》 were Douglas, James J.; Albright, Haley; Sevrin, Martin J.; Cole, Kevin P.; Stephenson, Corey R. J.. And the article was published in Angewandte Chemie, International Edition in 2015. Safety of Methyl 5-(chlorosulfonyl)-1-methyl-1H-pyrrole-2-carboxylate The author mentioned the following in the article:
In the presence of Ru(bpy)3Cl2 (bpy = 2,2′-bipyridine), 2-bromo-2,2-difluoroethyl arylsulfonates (and a styrenesulfonate) such as bromodifluoroethoxysulfonylthiophenecarboxylate I underwent chemoselective photochem. Smiles rearrangements mediated by Bu3 and HCO2H in DMSO to yield β-aryl-β,β-difluoroethanols such as II in 24-94% yields; a pyridinesulfonate and a chloropyrazolesulfonate were ineffective substrates in the photochem. Smiles rearrangement. Using the method, I was converted to the ORL-1 receptor antagonist III•HCl in five steps; the photochem. step could be conducted on 15 g scale using 0.01 mol% of the ruthenium catalyst, and the overall route compares favorably to the current synthetic sequence for III. The bromodifluoroethyl esters were prepared in two steps from Et bromodifluoroacetate via reduction to 2-bromo-2,2-difluoroethanol which was prepared on 40 g scale. 2-Bromo-2,2-difluoroethanol is volatile and a lachrymator and should be handled in a hood, and the photochem. Smiles rearrangements generate toxic SO2 gas as a byproduct. In the experiment, the researchers used Methyl 5-(chlorosulfonyl)-1-methyl-1H-pyrrole-2-carboxylate(cas: 306936-53-8Safety of Methyl 5-(chlorosulfonyl)-1-methyl-1H-pyrrole-2-carboxylate)
Methyl 5-(chlorosulfonyl)-1-methyl-1H-pyrrole-2-carboxylate(cas: 306936-53-8) belongs to pyrroles. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme.Safety of Methyl 5-(chlorosulfonyl)-1-methyl-1H-pyrrole-2-carboxylate
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics