Pyridine → Methyl 5-formyl-2-thiophenecarboxylate oxime

Beteiligte Stoffe

Reaktionsschritte

A solution of methyl 5-formyl-2-thiophenecarboxylate, prepared according to Example 10, (6.26 g, 36.78 mmoles), hydroxylamine hydrochloride (3.07 g, 44.14 mmoles) and pyridine (3.49 g, 44.14 mmoles) in 200 ml of ethanol was refluxed for 2 hours. The ethanol was removed in vacuo, the residue dissolved in ether and washed with water. The organic layer was dried (magnesium sulfate) and evaporated to a yellow solid. Trituration with a small amount of ether furnished the title compound as a white solid (4.93 g, 72%), m.p. 164°-7° C. Oxime Z:E ratio:(82:18).

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