5-Bromosalicylaldehyde → 5-(2,3-Dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-hydroxybenzaldehyde

Participants

Reaction Conditions

Reaction Steps

The synthesis of this compound is depicted schematically in FIG. 13. A 50 mL schlenk flask was charged with 5-bromosalicylaldehyde (2.408 g, 11.98 mmol) and Cl2Pd(PPh3)2 (0.420 g, 0.599 mmol, 0.05 equiv). To this was added 2-tributylstannyl-3,4-ethylenedioxythiophene (8.784 g, 20.37 mmol, 1.7 equiv) in 25 mL of DMF. The reaction mixture was heated to 80° C. for 18 h, over which time the reaction color changed from light yellow to dark red. The solvent was removed under vacuum and the resulting oil was dissolved in 350 mL of EtOAc and washed with dil. NH4Cl (6×100 mL). The organic layer was filtered through a pad of silica and the solvent was removed to yield a thermally- and light-sensitive yellow-green solid (0.846 g, 3.23 mmol, 27%), mp 132° C., dec. 1H NMR (CDCl3) δ10.98 (s, 1H), 9.94 (s, 1H) 7.92 (d, 1H, J=2.3 Hz), 7.84 (dd, 1H, J=2.4 and 8.7 Hz), 7.00 (d, 1H, J=8.7 Hz), 6.29 (s, 1H), 4.34-4.25 (m, 4H). MS m/z 262 (M+). HRMS (FAB) found m/z 263.0378 (M+H+); calcd for C13H11O4S m/z 263.0378 (M+H+).

Provenance & Evidence