A mixing test with an authentic sample of ester 3 [4] gave no depression of melting point, the 1H NMR
spectra of these compounds were identical.
Ethyl Ester of 2-(Indoline-1-carbonyl)-3-(indolin-1-yl)-3-oxopropionic Acid (5). Diester 2 (3.05 g,
0.01 mol) was maintained at 150°C for 15-20 min. The initial diester melts but after a certain time the reaction
product begins to crystallize. The reaction mixture was cooled, and treated with ether.The residue of ester 5 was
filtered off, washed with ether, and dried. Triethyl methanetricarboxylate of Rf 0.57 (Silufol UV 254, hexane–
ether, 1:1) was determined in the filtrate by comparison with an authentic specimen. The residue on the filter was
crystallized from ethanol and ester 5 (1.51 g, 80%) was obtained; mp 214-216°C (capillary was placed in the
instrument previously heated to 200-205°C for determining mp). 1H NMR spectrum, δ, ppm (J, Hz): 8.05 (2H, d,
J = 7.8, 2H-7); 7.26 (2H, d, J = 7.2, 2H-4); 7.18 (2H, t, J = 7.5, 2H-6); 7.04 (2H, t, J = 7.2, 2H-5); 5.48 (1H, s,
CH); 4.23 (2H, q, J = 7.0, OCH2); 4.05 (4H, t, J = 8.4, 2NCH2); 3.14 (4H, t, J = 8.4, 2NCH2CH2); 1.22 (3H, t, J
= 7.0, OCH2CH3). Found, %: C 69.95; H 5.77; N 7.32. C22H22N2O4. Calculated, %: C 69.83; H 5.86; N 7.40.
Methanetri-N-(indolin-1-yl)carboxamide (4) was obtained by the thermolysis of ester 5 at 220°C by
the method of the previous experiment in 85% yield. The triethyl methanetricarboxylate formed was determined
1
chromatographically as described above; mp 325-327°C (DMF) (lit. mp 320°C [2]). H NMR spectrum, δ, ppm
(J, Hz): 8.08 (3H, d, J = 7.5, 3H-7); 7.26 (3H, d, J = 7.7, 3H-4); 7.18 (3H, t, J = 7.8, 3H-6); 7.04 (3H, t, J = 7.5,
3H-5); 5.59 (1H, s, CH); 4.12 (6H, t, J = 8.4, 3NCH2); 3.15 (6H, t, J = 8.3, 3NCH2CH2).
(Indolin-1-yl)amide of 1-Hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo[3,2,1-ij]quinoline-2-carboxylic
Acid (6). Ester 5 (3.78 g, 0.01 mol) was added in small portions with stirring to diphenyl oxide (25 ml) heated to
220°C. The reaction mixture was cooled 15 min after adding all the ester 5, hexane (50 ml) was added, and
thoroughly mixed. The separated solid amide 6 was filtered off, washed with hexane, and dried. Yield 2.43 g
1
(91%); mp 244-246°C (ethanol). H NMR spectrum, δ, ppm (J, Hz): 10.68 (1H, s, OH), 6.94-7.70 (7H, m,
H arom.); 4.10-4.46 (4H, m, 2NCH2); 3.23-3.40 (4H, m, 2NCH2CH2). Found, %: C 72.39; H 4.97; N 8.34.
C20H16N2O3. Calculated, %: C 72.28; H 4.85; N 8.43.
REFERENCES
1.
A. Yegorova, A. Karasyov, A. Duerkop, I. Ukrainets, and V. Antonovich, Spectrochim. Acta, Part A, 61,
109 (2005).
2.
3.
A. Kutyrev and T. Kappe, J. Heterocycl. Chem., 34, 969 (1997).
S. Jönsson, G. Andersson, T. Fex, T. Fristedt, G. Hedlund, K. Jansson, L. Abramo, I. Fritzson,
O. Pekarski, A. Runström, H. Sandin, I. Thuvesson, and A. Björk, J. Med. Chem., 47, 2075 (2004).
I. V. Ukrainets, L. V. Sidorenko, O. V. Gorokhova, and O. V. Shishkin, Khim. Geterotsikl. Soedin., 718
(2006).
I. V. Ukrainets, O. V. Gorokhova, L. V. Sidorenko, V. B. Rybakov, and V. V. Chernyshev, Zh. Org.
Farm. Khim., 1, Issue 3-4, 45 (2003).
4.
5.
6.
7.
8.
Yu. V. Zefirov and P. M. Zorkii, Usp. Khim., 58, 713 (1989).
H.-B. Burgi and J. D. Dunitz, Struct. Correl., Vol. 2, VCH, Weinheim (1994), p. 741
I. V. Ukrainets, P. A. Bezugly, V. I. Treskach, S. V. Taran, and O. V. Gorokhova, Tetrahedron, 50,
10331 (1994).
9.
10.
H. R. Snyder (editor), Organic Syntheses, Vol. 28, John Wiley & Sons, New York (1948), p. 38.
G. M. Sheldrick, SHELX97. PC Version. A System of Computer Programs for Crystal Structure Solution
and Refinement, Rev. 2 (1998).
1037