反应详情

A mixture of ethyl hexahydro-4-oxoazepine-1-carboxylate (0.585 mol), 1,2-ethane-diol (0.585 mol) and p-toluenesulfonic acid (0.0058 mol) in toluene (800 ml) was stirred and refluxed overnight, using a water separator (10.5 ml was separated). The solvent was evaporated, yielding 142.5 g of ethyl 1,4-dioxa-8-azaspiro[4.6]undecane-8-carboxylate (intermediate 4).

1. temperaturerefluxed overnight
2. customa water separator (10.5 ml was separated)
3. customThe solvent was evaporated