HIGHLY FLUORINATED HETEROCYCLES. PART XVI. POLYFLUORINATED DERIVATIVES OF 1-METHYLPYRROLIDINE, 1-METHYLPYRROL-3-INE AND 1-METHYLPYRROLE

Article abstract of DOI:10.1016/S0022-1139(00)84958-1

Fluorination of 1-methylpyrrole with cobalt(III) fluoride gave six major products, 1-fluoromethyl- and 1-difluoromethyl- -octa-,-3H-hepta-, and -3H,4H-hexa-fluoropyrrolidine.Similar fluorination of 1-methyl-pyrrolidine gave better total recoveries of the same six products, together with 1-trifluoromethyloctafluoropyrrolidine, and 1-fluoromethyl- and 1-difluoromethyl- -2H-heptafluoropyrrolidine. 1-Fluoromethyl- and 1-difluoromethyl- -3H-heptafluoropyrrolidine each gave the corresponding polyfluoropyrrol-3-ine on dehydrofluorination with potassium hydroxide, but the 1-difluoromethyl-2H-heptafluoride could not be dehydrofluorinated. 1-Methyl- and 1-fluoromethyl- -3H,4H-hexafluoropyrrolidine similarly gave the corresponding 3H-3-ine, but no pyrrole.Reaction of 1-methyl-3H,4H-hexafluoropyrrolidine with 'old' aluminium chloride gave a little 1-methyl-2,5-dichlorodifluoropyrrole, the only fluoropyrrole we have obtained so far.Freshly sublimed AlCl3 afforded 1-methyltetrachloropyrrole (obtained also from 1-methylpyrrole and sulphuryl chloride) : fluorination of this with KCo(III)F4 gave 1-methyl- and 1-fluoromethyl- -3,4-dichloro-tetrafluoropyrrol-3-ine.