Dimethylformamide → HCID 11234748, compound

Participants

Reaction Steps

The product from Example 144 was suspended in CH2Cl2 (25 mL) and treated with 2 M oxalyl chloride in CH2Cl2 (3.0 mL, 6.0 mmol). After the bubbling had subsided, N,N-dimethylformamide (300 μL) was added slowly over 15 minutes. After an additional hour, more N,N-dimethylformamide (100 μL) was added. After another 30 minutes, the mixture was concentrated and dissolved into CH2Cl2 (5 mL). N,O-Dimethylhydroxylamine hydrochloride (488 mg, 5.0 mmol) and pyridine (1 mL) were added, the reaction flask was placed in a water bath, and the mixture was stirred overnight, concentrated, diluted with 1,2-dichloroethane (5 mL), heated at 85□ C. for four hours, concentrated, and partitioned between CH2Cl2 and water. Saturated aqueous NaHCO3 was added until the pH of the aqueous phase exceeded seven. Then the aqueous phase was separated and extracted with CH2Cl2. The combined organic phases were washed consecutively with water and brine, dried (Na2SO4), and chromatographed on silica with a gradient of 0 to 4% MeOH/CH2Cl2 to provide the title compound as a viscous brown syrup (60% yield from ester). 1HNMR (300 MHz, CD3OD) δ 1.19 (s, 3H), 1.37-1.54 (m, 1H), 1.73-1.88 (m, 2H), 1.95-2.09 (m, 1H), 2.27-2.39 (m, 1H), 2.45-2.64 (m, 2H), 2.95-3.17 (m, 2H), 3.20-3.3 (m, 2H), 3.39 (s, 3H), 3.63 (s, 3H), 6.62 (s, 1H), 7.46-7.83 (m, 4H), 7.73-7.81 (m, 2H), 7.86 (s, 1H).

Provenance & Evidence