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

HRID 430737Notes

Reaction equation

Br[C:2]1[CH:9]=[C:6]([CH:7]=[O:8])[C:5]([OH:10])=[CH:4][CH:3]=1.C([Sn](CCCC)(CCCC)[C:16]1[S:17][CH:18]=[C:19]2[O:24][CH2:23][CH2:22][O:21][C:20]=12)CCC>CN(C=O)C>[CH2:22]1[CH2:23][O:24][C:19]2[C:20](=[C:16]([C:2]3[CH:9]=[C:6]([CH:7]=[O:8])[C:5]([OH:10])=[CH:4][CH:3]=3)[S:17][CH:18]=2)[O:21]1

Participants

Conditions

Temperature: 80 °C

Procedure

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+).

Workup

customThe synthesis of this compound
customThe solvent was removed under vacuum
dissolutionthe resulting oil was dissolved in 350 mL of EtOAc
washwashed with dil. NH4Cl (6×100 mL)
filtrationThe organic layer was filtered through a pad of silica
customthe solvent was removed

Sources & evidence

ORD record: ord-89622bb50fbd4fcdac4beb0932916d4d
Source dataset: uspto-grants-2001_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06323309B1

Reaction notes

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