Potassium Fluoride → Methyl 6-cyclohexyl-5-(3-formyl-2-thienyl)-4-(2-methoxy-2-oxoethyl)-4H-thieno[3,2-b]pyrrole-2-carboxylate

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Reaction Steps

Methyl 5-bromo-6-cyclohexyl-4-(2-methoxy-2-oxoethyl)-4H-thieno[3,2-b]pyrrole-2-carboxylate (prepared in analogy to Example 7, Step 2, substituting tert-butyl bromoacetate with methyl bromo acetate) and (3-formyl-2-thienyl)boronic acid (1.2 eq.) were dissolved in dioxane (0.1 M) and treated with spray-dried KF (3.3 eq.). The solution was degassed by bubbling argon and Pd(t-Bu3P)2 (0.24 eq.) was added, and the reaction mixture was left stirring overnight; the mixture was then absorbed on silica gel and the title compound isolated by chromatography (PE/EtOAc 9:1). Yield: 65%. 1H-NMR (400 MHz, CDCl3, 300 K, δ) 9.62 (s, 1H), 7.63 (s, 1H), 7.61 (d, 1H, J 5.5), 7.50 (d, 1H, J 5.5), 4.62 (s, 2H), 3.91 (s, 3H), 3.67 (s, 3H), 2.46-2.37 (m, 1H), 1.80-0.80 (m, 10H); MS (ES+) m/z 446 (M+H)+.

Provenance & Evidence