The structure of a metabolite of pholcodine produced by humans is shown, by spectroscopic and synthetic data, to be a morpholin-3-one (amide) derivative rather than the alternative morpholin-2-one ( lactone ) isomer. Acylation of diethanolamine leads to an N,O- diacyl product even when only 1 equiv. of acylating agent is used. A mechanism is proposed to account for this observation. The appropriately substituted diacyl product can be cyclized to give a morpholin-3-one derivative which can be coupled to morphine by using caesium carbonate to give the metabolite. Suitable morpholin-2-one systems were coupled with morphine in basic conditions to give the alternative metabolite structure whose lactone group hydrolysed on standing to form a hydroxy acid derivative.
人体产生的pholcodine代谢产物的结构通过光谱和合成数据显示为一种吗啶-3-酮(酰胺)衍生物,而不是另一种酮(内酯)异构体。乙二醇胺的酰化即使只使用1当量的酰化剂也会导致N,O-二酰基产物。提出了一个机制来解释这一观察结果。适当取代的二酰基产物可以被环化,得到一种吗啶-3-酮衍生物,可以通过使用碳酸铯与吗啶结合来产生代谢产物。适当的吗啶-2-酮体系在碱性条件下与吗啶结合,形成另一种代谢产物结构,其内酯基在静置时水解为羟基酸衍生物。