Formaldehyde → 9-hydroxymethyl-9-fluorene carboxylic acid

Participants

Reaction Conditions

Reaction Steps

9-fluorene carboxylic acid (4.98 g, 23.7 mmol) and anhydrous THF (300 ml) were introduced into a flame-dried reaction vessel in which the atmosphere had been replaced by nitrogen, the reaction solution was cooled to −78° C., and n-butyl lithium (41.0 ml of 1.6M hexane solution, 71.0 mmol) was added. After stirring the reaction solution at −78° C. for 30 minutes, paraformaldehyde (2.30 g, 75.0 mmol) dissolved in anhydrous THF (100 ml) was added at −78° C., and stirred at room temperature for 13 hours. Distilled water was added, the solution was extracted with ether, and the pH of the aqueous layer was adjusted to 2 using 1N hydrochloric acid. It was then extracted again with chloroform, and the organic layer was dried by anhydrous magnesium sulfate. The low-boiling fraction was distilled under reduced pressure with the rotary evaporator, and 4.21 g of crude product was thus obtained. The methylene chloride-insoluble fraction of this crude product was collected, and the target compound (4.60 g, 19.3 mmol, 80.5%) was thus obtained. 1H-NMR (500 MHz, CDCl3) d: 7.78 (d, J=7.5, 2H), 7.67 (d, J=7.5, 2H), 7.46 (dd, J=7.0, 2H), 7.54 (dd, J=8.0, 2H), 4.02(s, 4H).

Provenance & Evidence