4-Phenyl-5-propyl-thiophene-2-carboxylic acid methoxy-methyl-amide → 1-(4-Phenyl-5-propyl-thiophen-2-yl)-ethanone

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Reaction Steps

At 2° C. methylmagnesium bromide (1 mL, 1.7 M in THF) is added to a solution of 4-phenyl-5-propyl-thiophene-2-carboxylic acid methoxy-methyl-amide (900 mg, 3.11 mmol). The mixture stirred for 1 h before another portion (0.2 mL) of the Grignard reagent is added. Stirring is continued for 2 h. The mixture is diluted with water, extracted with EA and the organic extracts are dried over MgSO4 and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 5:4 to give 1-(4-phenyl-5-propyl-thiophen-2-yl)-ethanone (456 mg) as a yellow oil; LC-MS: tR=1.06 min, [M+1]+=245.14, 1H NMR (CDCl3): δ 7.59 (s, 1H), 7.47-7.32 (m, 5H), 2.87-2.81 (m, 2H), 2.54 (s, 3H), 1.76-1.63 (m, 2H), 0.95 (t, J=/.6 Hz, 3H).

Provenance & Evidence