Dimethyl Sulfoxide → Biphenyl-3,3',4,4'-tetracarbaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of oxalyl chloride 2M in dichloromethane (DCM) (2.8 mL, 5.6 mmol, 4.4 molar equivalents) cooled to −78° C. is added dropwise a solution of dimethylsulfoxyde (DMSO) (0.8 mL, 11.1 mmol, 8.8 molar equivalents) in DCM (10 ml). The solution is stirred at −78° C. for 5 min and 3,3′,4,4′-tetra(hydroxymethyl)-1,1′-biphenyl 1c (0.22 g, 1.3 mmol, 1.0 molar equivalent) dissolved in a mixture of DCM-DMSO (1 ml-2 ml) is added dropwise. The solution is stirred for 1 h at −78° C. and triethylamine (6 mL) is slowly added at −78° C. The reaction mixture is stirred 10 minutes at −78° C. and slowly warmed up to room temperature. Ice-cold water (30 ml) is added to the reaction mixture and the aqueous layer extracted with DCM (3×30 ml). The organic fractions are combined, dried over magnesium sulfate, filtered and concentrated in vacuum to give a brown oil. Purification by column chromatography on silica gel (eluent: hexane-ethyl acetate 6/4) gave the title compound as an off-white powder (90 mg, 42%). 1H NMR (300.13 MHz, CDCl3) δ (ppm) 8.02 (dd, J1=8.1, J2=1.8 Hz, 2H) 8.14 (d, J=8.1 Hz, 2H) 8.28 (d, J=1.8 Hz, 2H) 10.58 (s, 2H) 10.68 (s, 2H).

Herkunft & Nachweise