1,2-Naphthoquinone → 4-propyl-3,4-dihydro-2H-naphtho[1,2-b][1,4]oxathiepine-6,7-dione

To a solution of naphthalene-1,2-dione (1.5 g, 9.5 mmol) in acetonitrile (50 mL) was added 3-mercaptohexan-1-ol (1.6 g, 11.9 mmol) followed by the addition of diisopropylethylamine (1.65 mL, 9.5 mmol). The mixture was stirred at room temperature for 30 minutes. The solvent was removed under reduced pressure and the residue dissolved in ethyl acetate (50 mL). The organic layer was washed with water (30 mL), dried with sodium sulfate and concentrated under reduced pressure. The resulting residue was dissolved in acetonitrile (35 mL) and reacted with p-toluenesulfonic acid (1.9 g). The reaction mixture was stirred at room temperature for 40 min and solvent removed under reduced pressure. Crude product was purified by flash column (5% EtOAc in hexane to 15% EtOAc in hexanes) to give product as purple solid (0.170 g). M.p.=74-75° C. (decomposition); 400 MHz 1H NMR (DMSO-d6) δ: 7.88 (d, J=7.2 Hz, 1H), 7.73 (m, 2H), 7.56 (m, 1H), 5.08 (m, 1H), 4.67 (m, 1H), 3.58 (m, 1H), 1.40-1.82 (m, 6H), 0.89 (brt, 3H); LCMS: 289 [M+H].

1. customThe solvent was removed under reduced pressure
2. dissolutionthe residue dissolved in ethyl acetate (50 mL)
3. washThe organic layer was washed with water (30 mL)
4. dry with materialdried with sodium sulfate
5. concentrationconcentrated under reduced pressure
6. dissolutionThe resulting residue was dissolved in acetonitrile (35 mL)
7. customreacted with p-toluenesulfonic acid (1.9 g)
8. stirringThe reaction mixture was stirred at room temperature for 40 min
9. customsolvent removed under reduced pressure
10. customCrude product was purified by flash column (5% EtOAc in hexane to 15% EtOAc in hexanes)

ORD record

ord-7bbda2be2a8041c89252b6b896d18e7e

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08067459B2