Morphine semi synthesis

Opium is a cmde exudate obtained from the opium poppy Papaver somniferum, and it provides several medicinally useful alkaloids. One of these is codeine, which is widely used as a moderate analgesic. Opium contains only relatively small amounts of codeine (1-2%), however, and most of the codeine for dmg use is obtained by semi-synthesis from morphine, which is the major component (12-20%) in opium. Conversion of morphine into... 

The same type of reasoning allows production of pholcodine, an effective cough suppressant, from morphine. In this semi-synthesis, the electrophile is Ai-(chloroethyl)morpholine, and the leaving group is chloride. 

Both morphine and codeine are valuable analgesics. Morphine is extracted from opium, the dried latex of the opium poppy, and codeine is usually obtained from morphine by semi-synthesis (see Box 6.2), since the amounts in opium are rather small. Thebaine is a valuable raw material for semi-synthesis of a wide range of morphine-like drugs. 

Thebaine (Figure 6.50) differs structurally from morphine/codeine mainly by its possession of a conjugated diene ring system. It is almost devoid of analgesic activity, but may be used as a morphine antagonist. Its main value is as substrate for the semi-synthesis of other drugs (see below). 

Morphinans (compactly fused Phe, C6, C5N, C6 and C40 rings) Codeine (opium-derived addictive, analgesic, antitussive, spasmolytic narcotic) morphine (opium-derived addictive, analgesic, antitussive, sedative, spasmolytic narcotic heroin is the semisynthetic diacetate) thebaine (non-analgesic, toxic, convulsant narcotic and semi-synthesis precursor of the anti-addiction drug naltrexone). 

Since for general clinical use morphine has a number of disadvantages the main one of which is its addictive property, many attempts have been made to modify the structure by semi-synthesis even before the structure had been fully established (ref.64). In parallel with the use of morphine and thebaine as natural intermediates many compounds having a simple structural resemblance to morphine have been studied for their potential analgesic activity without addictive and other side effects (ref.65), a search which continues to this day. 

Table 4 Semi-Synthesis of certain Derivatives of Morphine...

---