STUDY DATA FROM E.H. CHUKHAJIAN AND COLLEAGUES UPDATE UNDERSTANDING OF HETEROCYCLIC CHEMISTRY
Science Letter
July 8, 2008
HETEROCYCLIC CHEMISTRY
According to recent research published in the
Journal of Heterocyclic Chemistry, "Dialkylpropyn-1-yi(or
allyl)(3-isopropenylpr opyn-2-yl)ammonium bromides under base-catalyzed
condition instantly undergo intramolecular cyclization. The cyclization
of dialkylpropyn-1-yl(3-isopropenylpropyn-2-yl)ammoni um bromides
leads to the formation of 2,2-dialkyl-5-methylisoindolinium salts."
"In case of allyl analogs, instead of the expected
2,2-dialkyl-6-methyl-3a,4-dihydroisoindol inium salts their isomeric
forms – 2,2-dialkyl-5-methyl-2,6,7,7a-tetrahydro-1H-isoind olium
bromides are obtained. In alkaline medium they are transform into the
dihydroisoindolinium salts, the cleavage of which in two directions –
1,2 and 1,6 leads to the mixture of isomeric dialkyl-1,4-dimethyl-
and 2,4-dimethylbenzyl-amines," wrote E.H. Chukhajian and colleagues
(see also Heterocyclic Chemistry).
The researchers concluded: "Study of the behavior of
2,2-dialkyl-5-methylisoindolinium salts under conditions of water-base
cleavage showed, that only spiro[5-methylisoindolyn]morpholinium
bromide undergoes 1,2-elimination, forming 5-methylisoindoline 2-vinyl
ethyl ester."
Chukhajian and colleagues published their study in
the Journal of Heterocyclic Chemistry (Cyclization of
dialkylpropyn-1-yl(Allyl)(3-isopropenylpropyn-2 -yl)ammonium
bromides and water-base cleavage of
2,2-dialkyl-5-methyl-2,6,7,7a-tetrahydro-1H-iso indolium and
2,2-dialkyl-5-methylisoindolinium bromides. Journal of Heterocyclic
Chemistry, 2008;45(3):687-692).
For additional information, contact E.H. Chukhajian, National Academy
Science Republ Armenia, Institute Organ Chemical, Yerevan 375091,
Armenia.
The publisher’s contact information for the Journal of Heterocyclic
Chemistry is: Hetero Corporation, PO Box 170, Provo, UT 84603-0170,
USA.