Applying Gewald reaction for the preparation of some novel aminothieno derivatives featuring noroxymorphone skeletal backbone

A group of noroxymorphone derivatives were subjected to Gewald reaction conditions to prepare their respective aminothieno products. In refluxing piperidine/ethanol, 1a–g reacted with elemental sulfur and malononitrile to produce 2a–g in high yields. Reactions took place in one pot and completed within 4–7 h and products precipitated spontaneously in the reaction mixtures.