Dimethyl Sulfoxide → HCID 67438705, compound

Participants

Reaction Conditions

Reaction Steps

In an oven-dried 250 mL round-bottom flask was dissolved oxalyl chloride (9.54 mL, 19.08 mmol) in methylene chloride (40 mL) to give a colorless solution at −55° C. under nitrogen. DMSO (2.71 mL, 38.2 mmol) was added dropwise slowly over 2 min. After the solution was stirred for an additional 30 min, (6S,9S)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-6-ol (2.91 g, 8.67 mmol) (crude, azeotroped with dry benzene) dissolved in 8 mL methylene chloride (plus 8 mL rinse) was added via cannula over 5 min. The reaction mixture was stirred at −50 to −55° C. for an additional 40 min. Triethylamine (6.04 mL, 43.4 mmol) was added via syringe at −50° C. and the reaction mixture was gradually warmed up to −20° C. for 30 min. TLC showed complete conversion. Water and ethyl acetate were added, and the layers were separated. The aqueous layer was extracted with ethyl acetate. The combined organic layers were dried with sodium sulfate, and concentrated to give a tan oil. Purification by FCC up to 50% ethyl acetate/hexane afforded the desired product as a light yellow oil (2.08 g, 72%). MS(ESI)[M+H+]=334.35; 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.39 (d, J=5.04 Hz, 1H) 7.49 (d, J=7.55 Hz, 1H) 7.19 (dd, J=7.55, 4.78 Hz, 1H) 5.26 (dd, J=4.78, 2.27 Hz, 1H) 4.69 (d, J=14.35 Hz, 1H) 3.29 (d, J=14.35 Hz, 1H) 3.02 (ddd, J=12.15, 9.00, 6.04 Hz, 1H) 2.45-2.59 (m, 1H) 2.31-2.45 (m, 1H) 2.06-2.25 (m, J=8.53, 8.53, 5.98, 2.39 Hz, 1H) 1.06-1.19 (m, 3H) 1.01 (d, J=7.30 Hz, 9H) 0.89-0.97 (m, 9H).

Provenance & Evidence