NITROGEN BRIDGEHEAD COMPOUNDS PART 90 - AN EFFICIENT VERSATILE SYNTHESIS OF 1-METHYL-2-SUBSTITUTED ETRAHYDRO-6H-PYRAZINO[2,1-B]QUINAZOLINE-3,6-DIONES

Authors
KOKOSI J ALMASI J PODANYI B FEHER M BOCSKEI Z SIMON K HERMECZ I
Citation
J. Kokosi et al., NITROGEN BRIDGEHEAD COMPOUNDS PART 90 - AN EFFICIENT VERSATILE SYNTHESIS OF 1-METHYL-2-SUBSTITUTED ETRAHYDRO-6H-PYRAZINO[2,1-B]QUINAZOLINE-3,6-DIONES, Heterocycles, 48(9), 1998, pp. 1851-1866
Citations number
29
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Heterocycles → ACNP
ISSN journal
03855414
Volume
48
Issue
9
Year of publication
1998
Pages
1851 - 1866
Database
ISI
SICI code
0385-5414(1998)48:9<1851:NBCP9->2.0.ZU;2-J
Abstract
A versatile synthesis of 2-substituted 1-methyl- and etrahydro-6H-pyra zino[2,1-b]quinazoline-3,6-diones is presented, starting from 2-(1-bro moethyl)quinazolin-4(3H)-one. The key step of the reaction sequence is the diastereoselective cyclization of 2-{[1 -(N-2-haloacyl-N-substitu ted amino]ethyl}quinazolin-4(3H)-ones. Usually 1,4-dimethyl derivative s are obtained as pure racemic cis-compounds (2-alkyl and 2-benzyl der ivatives), or a mixture of diastereomers, containing the 4-methyl grou p in quasiaxial position.