78903-06-7Relevant articles and documents
REACTIONS OF NITROGEN-CONTAINING HETEROCYCLIC COMPOUNDS WITH HEXAFLUORO-BUT-2-YNE
Davidson, Jack L.,Murray, Ian E. P.,Preston, Peter N.
, p. 1601 - 1627 (2007/10/02)
Benzimidazole and a series of 2-substituted derivatives react with hexafluoro-but-2-yne (HFB) to form a series of 1-(3,3,3-trifluoro-1-trifluoromethylpropenyl) derivatives; a 1:2 addition product with HFB is formed by benzimidazol-2-ylmethannol and a spontaneous decarboxylation occurs in the reaction with benzimidazole-2-carboxylic acid. 2H-Benzimidazole-2-thione is transformed by HFB into a dihydrothiazolo benzimidazole.A condensed thiazolium salt (8a) is converted by HFB in methanol into an uncharacterised compound (9) of molecular formula C19H18F3N3O3S.Three of the benzimidazole-HFB adducts (4a,d,f) have been used to prepare new benzimidazoles, the most notable being the derivatives (10a,b) of the hitherto unreported 1H,3H-oxazolobenzimidazole ring system.Pyridine-2(1H)-thione with HFB affords a mixture of meso- and (+)-bis-(2-pyridylthio) butane derivatives (11a,b), but only the meso-isomer could be isolated from an analogous reaction with pyrazole.Reactions of HFB with 2-mercaptopyrimidine, 6-mercaptopurine and adenine N1-oxide occur by electrophilic attack at S and/or N to give products in the last two cases of undefined regiochemistry.The reaction of quinoline N-oxide with HFB is sensitive to a solvent effect: in tetrahydrofuran the major product is 2-(2,2,2-trifluoroethyl)quinoline.
