Aurelius (Hive Addict)
01-17-03 16:41
No 399055
      Preparation of Benzylamine  Bookmark   

Preparation of Benzylamine:
Patent GB619827

Example 1:

60g of benzyl chloride, 60 of urea and 40cc of water are refluxed for 5 hours, after which unreacted benzyl chloride is removed by steam distillation.  The mixture is then allowed to cool and the crude benzyl urea is removed by filtration.  The benzyl urea may be recrystallized from water. Benzyl urea thus obtained has; MP: 142-143C, Yield: 42g

42g of benzyl urea and 50g of caustic soda are heated together to an internal temperature of the order of 250C.  and the crude benzylamine formed is distilled.  The crude benzylamine can be purified by aspirating with nitrogen to remove ammonia and redistilling. Yield: 30g

 
 
 
 
    java
(Hive Bee)
01-18-03 00:45
No 399194
      Re: Benzylamine synthesis  Bookmark   

I found your post interesting and it reminded me of something I recently read in March's 5th edition. Oxidation of Primary Halides and Esters of Primary Alcohols to Aldehydes Section 9-19 and on page 1536 starting with " An other way to oxidize primary alkyl halides  to aldehydes is by the use of hexamethylenetetramine"( Aldrich $~80/kg)" followed by water . However , this reaction, called the sommelet reaction, is limited to benzylic halides. The reaction is seldom useful when the R in RCH2CL is alkyl, the first part of the reaction is conversion to the amine ArCH2NH2, which can be isolated. Reaction of the amine with excess of hexamethyleneterramine gives the aldehyde. It is this last step that is the actual Sommelet reaction, though the entire process can be conducted without isolation of intermediates. Once the amine is formed, it is converted to an imine(ArCH2N=CH2) with formaldehyde liberated from the reagent. The key step the follows: Transfer of hydrogen from another mole of the arylamine to the imine. This last imine is the hydrolyzed by water to the aldehyde. Alternatively, the benzyamine may transfer hydrogen directly to hexamethylenetetramine".

Ref:  for a review otf the Sommlet reaction , see Angyal,S.J. Org. React., 1954,8,197

...................hence the benzylamine synthesis and as an extra a benzaldehyde ............java


Saludos , from Latin America