ISSN:
0170-2041
Keywords:
Homohistamine
;
Imidazole derivatives
;
2-Propenamine derivatives
;
Impromidine
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Synthesis of (Z)- and (E)-3-(1H-imidazol-4-yl)-2-propenamine and Some 3-(1H-imidazol-4-yl)propanamines3-(1H-Imidazol-4-yl)propanamine (6, homohistamine), an essential intermediate for the synthesis of potent impromidine-type histamine H2 receptor agonists, is efficiently prepared from trans-urocanic acid (1) by reduction of the methyl ester 2 and conversion to the saturated amide 4. Dehydration with thionyl chloride yields the nitrile 5 which is subsequently reduced to 6. Side-chain methylated 3-(1H-imidazol-4-yl)propanamines 12 are available from 1H-imidazole-4-carbaldehyde (7) and 1-(1H-imidazol-4-yl)ethanone (8), respectively, via unsaturated nitriles 10 and stepwise reduction. Cyclization of the appropriate 4-bromo-5-oxohexanenitriles 14α with formamidine in liquid ammonia and reduction of the obtained nitriles 15 furnishes ring-methylated amines 16. (E)-3-(1H-Imidazol-4-yl)-2-propenamine [(E)-23] is obtained in six steps from the trans-ester 2 while (Z)-23 is accessible by treating 7 with triphenyl(2-phthalimidoethyl)phosphonium bromide (17) and final deprotection. These primary amines are valuable intermediates for the synthesis of impromidine analogues.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199219920158
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