2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 49856566, compound

Temperature

-10 °C

Trimethylsilyldiazomethane (0.12 mL, 2.0 M in diethyl ether, 0.25 mmol) was added dropwise to a suspension of 22 (110 mg, 0.19 mmol) in methanol (1 mL) and THF (3 mL) at −10 to 0° C., and the mixture was stirred at −10° C. for 30-45 min after addition. The solvent was removed under reduced pressure at 20-25° C. The residue (24, cis-trans mixture) was dissolved in anhydrous 1,4-dioxane (5 mL) and DDQ (100 mg, 0.44 mmol) was added to the solution. The reaction mixture was heated at reflux for 3-4 h. 1,4-Dioxane was evaporated under reduced pressure and chloroform (30 mL) was added to the residue. The mixture was washed with sodium bicarbonate (5%, 2×10 mL), water (15 mL), dried with sodium sulfate, and filtered through a thin layer of silica gel, eluting with chloroform. The combined filtrates were evaporated under reduced pressure. The amorphous solid containing 26 was added to a stirred solution of KOH (180 mg, 18.5 mmol) in water-ethylene glycol mixture (1+3 mL) at room temperature, and the mixture was heated at reflux on oil bath for 24 h. After the mixture was cooled to room temperature, it was diluted with water (5 mL) and acidified with acetic acid (0.5 mL). The white precipitate was collected by filtration to obtain 28 as a white powder (24 mg, 47%): mp 313° C. IR (KBr) 1650, 1604 cm−1; 1H NMR (500 MHz, DMSO-d6) δ 11.85 (s, 1 H), 9.36 (s, 1 H), 8.02 (d, J=8.3 Hz, 1 H), 7.71 (s, 1 H), 7.54 (t, J=7.6 Hz, 1 H), 7.44 (d, J=8.1 Hz, 1 H), 7.23 (t, J=7.6 Hz, 1 H), 4.51 (t, J=6.8 Hz, 2 H), 4.43 (t, J=4.8 Hz, 1 H), 3.92 (s, 3 H), 3.91 (s, 3 H), 3.22 (dd, J=10.8, 5.5 Hz, 2 H), 2.05-1.81 (m, 2 H); 13C NMR (126 MHz, DMSO-d6) δ 162.82, 160.88, 152.96, 149.17, 144.41, 137.37, 130.28, 128.54, 126.19, 121.07, 118.95, 115.89, 113.14, 107.83, 107.40, 57.90, 55.63, 55.50, 48.77, 31.35; positive ESIMS m/z (rel intensity) 381 (MH+, 100). Anal. Calcd for C21H20N2O5: C, 66.31; H, 5.30; N, 7.36. Found: C, 66.03; H, 5.16; N, 7.26.

1. additionafter addition
2. customThe solvent was removed under reduced pressure at 20-25° C
3. dissolutionThe residue (24, cis-trans mixture) was dissolved in anhydrous 1,4-dioxane (5 mL)
4. temperatureThe reaction mixture was heated
5. temperatureat reflux for 3-4 h
6. custom1,4-Dioxane was evaporated under reduced pressure and chloroform (30 mL)
7. additionwas added to the residue
8. washThe mixture was washed with sodium bicarbonate (5%, 2×10 mL), water (15 mL)
9. dry with materialdried with sodium sulfate
10. filtrationfiltered through a thin layer of silica gel
11. washeluting with chloroform
12. customThe combined filtrates were evaporated under reduced pressure
13. additionThe amorphous solid containing 26
14. temperaturethe mixture was heated
15. temperatureat reflux on oil bath for 24 h
16. temperatureAfter the mixture was cooled to room temperature
17. filtrationThe white precipitate was collected by filtration

ORD record

ord-adf09890a8004689bd88b69c0646eaca

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09073920B2