N-Halogeno compounds. Part 16. Perfluoro-[N-fluoro-N-(4-pyridyl)acetamide] - A new site-selective electrophilic fluorinating agent

Article abstract of DOI:10.1016/0022-1139(95)03380-7

Perfluoro-[N-fluoro-N-(4-pyridyl)acetamide] (2), prepared via direct fluorination of the sodium salt (4) of perfluoro-[N-(4-pyridyl)-acetamide], readily fluorinates diethyl sodio(phenyl)malonate [→PhCF(CO₂Et)₂], 1-morpholinocyclohexene(→2-fluorocyclohexanone), anisole (→2-and 4-FC₆H₄OMe), and phenol (→2-and 4-FC₆H₄OH) under mild conditions. The sodium salt precursor (4) of this side-chain N-F reagent (2) is easily made from pentafluoropyridine via the trifluoroacetylation of its 4-amino derivative or, more directly, by treating it with two equivalents of the monosodium salt of trifluoroacetamide.