Oxalyl chloride → 5-Iodo-1-oxo-2,3,7,8,10,11-hexahydro-1H-4-oxa-9-aza-cyclohepta[a]naphthalene-9-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

Into a 100 ml flask, the product from step (e) (312 mg, 0.72 mmol) dissolved in DCM (20 ml) was added. The solution was cooled to 0° C., and oxalyl chloride (94 μL, 1.07 mmol) was added, followed by 2 drops of DMF. After 30 minutes, volatiles were evaporated in vacuo and the residue was dissolved in fresh DCM (20 ml) and cooled to 0° C. Aluminum chloride (386 mg, 2.88 mmol) was then added and the reaction mixture stirred for 1 hour. The reaction was quenched with saturated aqueous NH4Cl, and the organic layer was extracted with DCM (3×). The combined DCM extracts were washed with brine, dried over Na2SO4, and solvent evaporated in vacuo to give the crude product. Purification by silica-gel chromatography (gradient elution: 0 to 40% EtOAc in hexanes) gave the sub-title compound as a light yellow solid (170 mg). 1H NMR (300 MHz, CDCl3) δ 7.69 (s, 1H); 4.56 (t, J=6.3 Hz, 2H); 4.12 (q, J=7.2 Hz, 2H); 3.68-3.51 (m, 6H); 2.85 (t, J=6.6 Hz, 4H); 1.23 (t, J=7.2 Hz, 3H); MS: ESI (positive): 416 (M+H).

Provenance & Evidence