Dimethyl Sulfoxide → 4-[5-[4-(2-Methylpropyl)phenyl]-1,2,4-oxadiazol-3-YL]benzaldehyde

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Reaction Steps

A solution of 9.8 mL (112.4 mmol) of oxalyl chloride in 300 mL of dichloromethane was treated with 12 mL (168.6 mmol) of DMSO at −78° C. To the reaction mixture, 16.5 g of 4-(5-(4-(2-methylpropyl)phenyl)-1,2,4-oxadiazol-3-yl)phenylmethanol (from Step B) was added followed by 78 mL (450 mmol) of N,N-diisopropylethylamine at −78° C. The reaction mixture was allowed to warm to rt over 1 h. Dichloromethane was removed under reduced pressure and the residue was partitioned between ethyl acetate and 0.5 N KHSO4 solution. The organic layer was washed with 1 N HCl solution, saturated NaHCO3 and water and then was concentrated to dryness. The crude product was recrystallized from hexanes to afford 11.9 g of the title compound: 1H NMR (400 Mhz) δ 0.97 (d, J=6.7, 6H), 1.97 (m, 1H), 2.61 (d, J=7.0, 2H), 7.37 (d, J=8.0, 2H), 8.06 (d, J=8.2, 2H), 8.16 (d, J=8.2, 2H), 8.39 (d, J=8.0, 2H), 10.14 (s, 1H); ESI-MS 307 (M+1H); LC-1: 4.5 min.

Provenance & Evidence