Ethylenediamine → 3-(tert-Butyloxycarbonyl)-7-(pyrazin-2-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine

Participants

Reaction Steps

To a stirred solution of 7-acetyl-3-(tert-butyloxycarbonyl)-2,3,4,5-tetrahydro-1H-3-benzazepine (12 g, 42 mmol) in dioxan (60 ml) was added selenium dioxide (4.61 g, 42 mmol) in dioxan (60 ml) and water (15 ml). The mixture was heated under reflux for 18 h., cooled and the solid residue filtered. The filtrate was evaporated in vacuo and the residue azeotroped with toluene to give an orange gum which was dissolved in ethanol and added dropwise to a stirred solution of ethylenediamine (3 g, 50 mmol) in ethanol at 0° C. After the addition was complete, KOH (2.6 g, 46 mmol) was added and the reaction heated under reflux for 3 h. The reaction mixture was then allowed to cool and evaporated in vacuo. The residue was partitioned between water and dichloromethane and the combined organic extracts dried and evaporated in vacuo to give a brown gum. Purification by silica gel chromatography (eluant 20% EtOAc:hexane) gave the title compound as a yellow oil (3.5 g).

Provenance & Evidence