Diacetylmorphine structure

The basic structure of morphine (Fig. 26.1) can be altered in rather minor ways that drastically change the effects of the drug. Acetylation of the hydroxyl groups leads to the synthesis of heroin (diacetylmorphine). 

The fabrication of imprinted monolithic solid-phase microextraction fibres has been developed for the selective extraction and preconcentration of diacetylmorphine and its structural analogues, triazines, bisphenol A, anaesthetics, and antibiotics followed by GC or HPLC analysis [156,163,179,196,197]. In addition, the on-line coupling of the imprinted monolith as a preconcentration column with a conventional analytical column has been proposed for the enrichment and cleanup of environmental and food samples [163]. However, at present, the capacity of the imprinted fibres and thus the degree of recovery of analytes are very variable and obviously need some improvement. For example, the recoveries of triazines after SPME with an imprinted monolith prepared by in situ polymerisation of MAA as... 

In recent years there has been a major research effort, so far without success, to produce potent, centrally acting analgesics that do not have an abuse potential. The discovery of various types of opioid receptor, which may have different effects on central neurotransmitter function, may ultimately lead to the development of such a drug. In the meantime, the most widely used opioids, for example morphine, heroin (also called diacetylmorphine) and codeine are therapeutically effective but are liable to be abused and produce dependence. The structure of some of the morphine-like analgesics and their antagonists are shown in Figure 15.2. 

Unfortunately, to feel pain is an essential condition for survival. Pain-initiated avoidance behavior protects the individual. Morphine, obtained from opium, from the juice of the opium poppy (Papaver somniferum), has been known for millennia to alleviate pain. As mentioned in Chapter 5, endogenous opioids have also been identified. The word opioid is now used to refer to all drugs with morphine-like actions. The structure of morphine is shown in Figure 11.11. Diacetylmorphine (heroin) is made by acetylation at the 3 and 6 positions. 

The correct structure of morphine was proposed in 1925. Ultimate proof of its correct structure had to await its total synthesis, accomplished three decades later. The lack of the correct structure of morphine did not discourage the synthesis of several morphine congeners and derivatives by chemical reaction with the known peripheral functional groups, specifically the phenolic hydroxyl (C-3), and allylic alcohol (C-6), and the double bond (C-7-8) (Fig. 5-8). Among the derivatives introduced before 1930 and still in common usage today are codeine,6 ethylmorphine (Dionin), diacetylmorphine (heroin), hydromor-phone (Dilaudid), hydrocodone (Dicodid), and methyldihydromorphinone (Metopon). 

Morphine was among the first compounds to undergo structure modification. Ethylmorphine (the 3-ethyl ether of morphine) was introduced as a medicine in 1898. Diacetylmorphine (heroin), which may be considered to be the first synthetic pro-drug, was synthesized in 1874 and marketed as a nonaddicting analgesic, antidiarrheal, and antitussive agent in 1898. 

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