Toluene → Tert-butyl 2-fluoro-6-formylphenylcarbamate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 2-fluorophenylcarbamate (42.7 g, 202 mmol) was concentrated from toluene in vacuo (3×) to remove any traces of water. The resulting residue was dissolved in tetrahydrofuran (600 mL), and cooled to −78° C. To this was added tert-butyllithium (1.7 M in pentane, 285 mL, 485 mmol) in dropwise fashion. After addition was complete, the reaction was stirred at −78° C. for 30 minutes. The solution was allowed to gradually warm to −20° C. before re-cooling to −78° C. To this was added dimethylformamide (46.9 mL, 606 mmol). The reaction was allowed to gradually warm to room temperature overnight. The reaction was poured into a separatory funnel containing diethyl ether and water. The organics were washed with water (3×) and concentrated. The combined aqueous washes were neutralized with 1 M potassium bisulfate and extracted with diethyl ether. The ethereal layers were combined with the other organics, washed with water, then brine, dried over magnesium sulfate, and concentrated to give 48.1 g (100%) as a yellow oil which was used without further purification. 1H-NMR (CDCl3, 500 MHz) δ 1.50 (s, 9H), 7.27 (m, 1H), 7.35 (m, 1H), 7.56 (d, J=7.6 Hz, 1H), 7.85 (bs, 1H), 9.99 (d, J=1.2 Hz, 1H). Mass spec.: 262.16 (MNa)+.

Provenance & Evidence