2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 67358352, compound

Participants

Reaction Conditions

Reaction Steps

(4-Oxo-3,4,5,6,7,8-hexahydro[1]benzothieno[2,3-d]pyrimidin-7-yl)acetate (5 g, 17.10 mmol, from step 2) was added to DDQ (9.71 g, 42.76 mmol, 2.5 equiv) in 1,4-dioxane (50 mL) solution under argon. The reaction mixture was heated to 90° C. for 15 h. The mixture was then allowed to cool to rt and the brown solid precipitated from solution. The solid was filtered and washed with 1,4-dioxane (2×30 mL). The filtrate was concentrated in vacuo. Saturated aqueous NaHCO3 (150 mL) was then slowly poured into the concentrated filtrate at 0° C. The mixture was stirred at 0° C. for 10 min then extracted with DCM (3×300 mL). The combined organic layer was washed with saturated aqueous NaHCO3 (100 mL), brine (30 mL) and dried (Na2SO4), then concentrated in vacuo. Ethyl ether (2×15 mL) was used to triturated the product. After drying, 1.78 g (6.18 mmol, 35%) of the desired product was obtained as a brown solid and it was used without further purification. 1H-NMR (CD3OD) δ 8.46 (d, J=8.1 Hz, 1H), 8.18 (s, 1H), 7.84 (s, 1H), 7.43 (d, J=8.2 Hz, 1H), 4.14 (q, 2H), 3.79 (s, 2H), 1.25 (t, 3H), LCMS RT=2.52 min, [M+H]+=289

Provenance & Evidence