6-cyano-7-fluoro-3,4-dihydro-2H-chromene-4-carboxylic acid → Tert-butyl 6-cyano-7-fluorochroman-4-carboxylate

Participants

Reaction Steps

6-Cyano-7-fluoro-3,4-dihydro-2H-chromene-4-carboxylic acid was dissolved in 10 mL of THF and treated with (Z)-tert-butyl N,N′-diisopropylcarbamimidate. After stirring for 3 hours, an additional 2 mL of (Z)-tert-butyl N,N′-diisopropylcarbamimidate was added and the reaction was stirred overnight. The reaction was diluted with ether, filtered, concentrated onto silica gel and flashed with 8:1 hexanes/ethyl acetate to provide the desired product (1.4 g, 64% yield) as a white solid.

Provenance & Evidence