Chemistry of Heterocyclic Compounds, Vol. 47, No. 12, March, 2012 (Russian Original Vol. 47, No. 12, December, 2011)
FIRST REPRESENTATIVE OF 6b,9-EPOXYISOINDOLO-
[2,1-a]QUINAZOLINE-10-CARBOXYLIC ACIDS
V. P. Zaytsev
1
*, F. I. Zubkov
1
, E. L. Motorygina
1
, M. G. Gorbacheva
1
,
E. V. Nikitina
1
, and A. V. Varlamov
1
Keywords: 2-furylquinazolin-4-ones, furfurylamines, isoindolo[2,1-a]quinazolines, Diels-Alder reaction,
intramolecular [4+2] cycloaddition.
We have developed a synthetic route for the preparation of epoxyisoindolones condensed with various
heterocycles based on the cycloaddition of unsaturated acid derivatives to -furyl-substituted hydrogenated
azaheterocycles [1]. To explore the synthetic scope of this method we have prepared the 3-alkyl-2-furyl-
quinazolines 1 by the method reported in [2] and studied their reaction with maleic anhydride for the first time.
Acylation of the quinazolin-4-ones 1a-c by refluxing with maleic anhydride in toluene is accompanied
by a spontaneous exo-[4+2] cycloaddition of an N-maleinamide fragment to the 2-furyl substituent [3, 4]. The
epoxyisoindoloquinazoline carboxylic acids 3a-c are formed as a single diastereomer with yields from moderate
to quantitative.
N
N
O
O
O
R
HO
2
C
O
O O
N
N
O
O
O
H
R
HO
2
C
O
O
H
RCH
2
NH
2
N
H
N
O
O
R
+
N
H
O
O
O
2a–c
1
2
4
5
6a
7
8
9
PhMe,
[4+2]
a R = Me; b R = 2-furyl; c R = Ph
10
3a–c
EtOH, H
+
1a–c
1
2
5
4
6
7
8
6b
3
, 4 h
_______
*To whom correspondence should be addressed, e-mail: vzaitsev@sci.pfu.edu.ru.
1
Peoples' Friendship University of Russia, 6 Miklukho-Maklaya St., Moscow 117198, Russia.
__________________________________________________________________________________________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp, 1909-1913, December 2011.
Original article submitted September 20, 2011.
0009-3122/12/4712-1603©2012 Springer Science+Business Media, Inc. 1603