Fluorene → 4,7-Difluoro-9H-fluoren-2-amine

Participants

Reaction Steps

(Namkung, M. J.; Fletcher, T. L.; Wetzel, W. H. Derivatives of Fluorene. XX. Fluorofluorenes. V. New Difluoro-2-acetamidofluorenes for the Study of Carcinogenic Mechanisms. J. Med. Chem. 1965, 8, 551-554, the disclosure of which is herein incorporated by reference). To a 25 mL round-bottomed flask containing 4,7-difluoro-9-oxo-2-fluorenamine (EXAMPLE 32) (158.5 mg, 0.686 mmol) in 4.25 mL glacial acetic acid was added red phosphorous (425 mg, 13.7 mmol, 20 equiv) and 57% aqueous HI (0.51 mL). The mixture was heated to reflux for 40 h, then evaporated to near-dryness by distillation. Boiling water (5 mL) was added, and the hot mixture was filtered. Upon addition of 10% NH4OH (20 mL), a white precipitate formed, and was filtered, washed with water, and dried under vacuum to afford 127 mg (85%) of 4,7-difluoro-2-fluorenamine as a white solid, mp 119°-120° C. (lit. mp 119.5°-121° C.). Data for 4,7-difluoro-2-fluorenamine: 1H NMR (400 MHz, CDCl3) 7.70 (dd, J=8.4, 5.2, 1H), 7.15 (dd, J=9.0, 2.0, 1H), 7.03 (app dt, J=9.0, 2.0,1H), 6.63 (s, 1H), 6.39 (dd, J=11.6, 1.7, 1H), 3.83 (s, 2H), 3.80 (br s, 2H).

Provenance & Evidence