ChemisTris
(Hive Bee)
12-12-02 13:06
No 388864
      4-Dimethylaminopyridine: catalyst in heroin synth
(Rated as: excellent)
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"4-Dimethylaminopyridine as a catalyst in heroin synthesis" - Forensic Science International 129 (2002) 194199.

Abstrct:
In this paper, we describe an acetylating method for fast synthesis of heroin from morphine in the presence of 4-
dimethylaminopyridine (4-DMAP) as a catalyst. In the reaction which led to heroin formation, the morphine base was subjected to a solution made up of 4-DMAP (catalyst), methylene chloride (solvent) and acetic anhydride (acetylating agent).

We showed that in comparison with classic acetylating procedures, reaction time can be reduced from at least several hours at elevated temperatures to <10 min at room temperature. In general, reaction time is dependant on the molar concentration ratio between morphine and 4-DMAP.

...

In this work, we describe a method of fast heroin synthesis, where 4-dimethylaminopyridine was used as a catalyst.

4-Dimethylaminopyridine, which has already been applied in some forensic investigations, has been reported as an excellent catalyst for acetylation of alcoholic and phenolic hydroxy groups. A recent review on catalysis by 4-dialkylaminopyridines is given in [15].
...

Acetylation of morphine:
To study acetylation of morphine by acetic anhydride in the presence of 4-dimethylaminopyridine, morphine base was subjected to a solution made up of 4-DMAP (catalyst),dichloromethane (solvent) and acetic anhydride (acetylating agent). Three experiments where reagents were mixed in different proportions were done.

Mixture 1: Morphine base (28.5 mg, 0.1 mmol); 4-dimethylaminopyridine(29.4 mg, 0.24 mmol); 1 ml of dichloromethane;0.1 ml (1.06 mmol) of acetic anhydride (Ac2O).

Mixture 2: Morphine base (28.5 mg, 0.1 mmol); 4-dimethylaminopyridine (29.4 mg, 0.24 mmol); 1 ml of dichloromethane; 0.025 ml (0.26 mmol) of acetic anhydride (Ac2O).
...

As can be seen in Fig. 3, all morphine was converted to diacetylmorphine in the reaction time of approximately 8 min at room temperature.


Conclusions
The synthesis of heroin in the acetylation reaction, where morphine is brought into a contact with an excess of acetic anhydride, is usually performed at elevated temperatures and the time needed for the acetylation to be completed is from several hours to a few days. We showed that in the presence of the catalyst 4-dimethylaminopyridine reaction time can be reduced to <10 min at room temperature.

The quantity of acetic anhydride is not a critical parameter for the reaction rate, of course, if we keep in mind that the minimum amount is defined by the reaction stoichiometry. The experiments showed that the reaction time is dependant on the molar concentration ratio between morphine and 4-DMAP.


http://www.forensic.esmartweb.com/heroin.dmap.catalyst.pdf


Got democracy?http://www.dhushara.com/book/multinet/democ/wed.htm
 
 
 
 
    Rhodium
(Chief Bee)
12-12-02 16:13
No 388941
      I have had it at ../rhodium/pdf/heroin....  Bookmark   

I have had it at ../rhodium/pdf /heroin.synthesis.pdf for a while, but I cannot find any links to it from here, so I must have forgotten to post about it.

Oh, I just found your page at http://www.forensic.esmartweb.com - Good job! Are you going to host a significant amount of forensic journal articles there? In that case I can contribute with several from my private collection of such stuff.
 
 
 
 
    ChemisTris
(Hive Bee)
12-12-02 16:44
No 388949
      I should of known  Bookmark   

I should of known you had the article Rhodium laugh
(I did UTFSE but I just din't check your /pdf list)

Are you going to host a significant amount of forensic journal articles there? In that case I can contribute with several from my private collection of such stuff.

Well I will attempt to keep some interesting bits and pieces up at that site (at the moment forensics is flavour of the month because it looks like I won't be doing it postgrad.)

Your private collection...tell me more cool.

 

Got democracy?http://www.dhushara.com/book/multinet/democ/wed.htm