Phenol → (Phenylmethyl)hydrazine

Participants

Reaction Steps

Triflate 12 was prepared from diethyl hydroxymethylphosphonate (2 g, 11.9 mmol), 2,6-lutidine (2.1 mL, 17.9 mmol), and trifluoromethanesulfonic anhydride (2.5 mL; 14.9 mmol) as described for compound 9. To a solution of phenol 8 (60 mg, 0.10 mmol) in THF (2 mL) was added Cs2CO3 (65 mg, 0.20 mmol) and triflate 12 (45 mg, 0.15 mmol) in THF (0.25 mL). The mixture was stirred at room temperature for 2 h and additional triflate (0.15 mmol) in THF (0.25 mL) was added. After 2 h the reaction mixture was partitioned between EtOAc and saturated NaCl. The organic phase was dried (MgSO4), filtered, and evaporated under reduced pressure. The crude product was chromatographed on silica gel (EtOAc) to give a residue that was purified by chromatography on silica gel (5% 2-propanol/CH2Cl2) to afford the diethylphosphonate as a foam: 1H NMR (CDCl3) δ 7.66 (d, 2H), 7.10 (d, 2H), 6.94 (d, 2H), 6.82 (d, 2H), 5.60 (d, 1H), 4.97 (d, 2H), 4.23-4.13 (m, 6H), 3.93-3.62 (m, 10H), 3.12-2.68 (m, 7H), 1.84-1.44 (m, 3H), 1.31 (t, 6H), 0.88-0.82 (2d, 6H); 31P NMR (CDCl3) δ 17.7; MS (ESI) 729 (M+H).

Provenance & Evidence