Synthese und Eigenschaften 6‐substituierter 4‐Alkoxy‐5,6‐dihydro‐4H‐thieno[3,2‐b]pyrrol‐5‐one

A novel route to the 5,6-dihydro-4-H-thieno[3,2-b]pyrrol-5-one ring system involving an intermediate substituted-thiophene synthesis

“…The residue was then purified by silica gel flash chromatography using 30% ethyl acetate in hexanes as eluant. Homogeneous fractions were combined and evaporated to afford the product 9 as a yellow, amorphous solid (840 mg 51%); 1 Ethyl (3-Amino-4-cyano-5-phenyl-thiophen-2-yl)-2-oxoacetate (15). α-Chlorobenzylidenemalononitrile (500 mg, 2.65 mmol) and ethyl mercaptopyruvate (470 mg, 3.18 mmol) were suspended in anhydrous ethanol (20 ml) at room temperature, and the mixture stirred vigorously while neat Et 3 N (268 mg, 2.65 mmol) was added via syringe.…”

“…In our ongoing efforts to synthesize bioisosteres of functionalized indoles such as oxindole, we became interested in the thienopyrrolone ring system. While an extensive literature exists on the synthesis of the related thienopyrroles [10,11], only a few groups discuss the preparation of thienopyrrolones [12][13][14][15][16]. A common feature in many of these reports is the need to employ highly substituted thiophenes as starting materials, many of which are difficult to prepare.…”