Helvetica Chimica Acta – Vol. 89 (2006)
2921
2
,5-Diethyl 1,3-Dimethyl Benzene-1,2,3,5-tetracarboxylate (1b). Yield: 0.24 g (36%). Colorless crys-
1
3
tals. M.p. 99–1018. IR (KBr): 1730, 1728, 1727 (4 C=O); 1433; 1242. H-NMR: 1.41 (t, J=7.2, Me),
.44 (t, J=7.2, Me); 3.94 (s, 2 MeO); 4.45 (q, J=7.2, CH O); 4.89 (q, J=7.2, CH O); 8.82 (s, 2 CH).
C-NMR: 13.9 (Me); 14.3 (Me); 52.9 (2 MeO); 62.0 (CH O); 62.2 (CH O); 129.2 (C); 131.5 (C);
3
3
3
1
2
2
1
3
2
2
+
1
(
35.0 (2 CH); 140.4 (C); 164.3, 164.5, 167.5 (4 C=O). EI-MS: 338 (4, M ), 293 (100), 265 (33), 149
(338.32): C 56.80, H 5.36; found: C 56.71, H 5.40.
51), 71 (39), 57 (91). Anal. calc. for C H O
ACHTREUNG
16
18
8
1
,3-Diethyl 2,5-Dimethyl Benzene-1,2,3,5-tetracarboxylate (1c). Yield: 0.26 g (38%). Colorless pow-
1
3
der. M.p. 87–898. IR (KBr): 1722, 1725, 1729 (4 C=O); 1461; 1299. H-NMR: 1.34 (t, J=7.2, 2 Me);
.95 (s, MeO); 4.10 (s, MeO); 4.32 (q, J=7.2, 2 CH O); 8.93 (s, 2 CH). C-NMR: 14.0 (Me); 53.4
3
13
3
2
(
(
MeO); 53.5 (MeO); 61.7(2 CH O); 128.4 (C); 128.5 (C); 129.5 (2 CH); 154.4 (C); 159.2, 159.8, 162.8
4 C=O). EI-MS: 338 (7, M ), 230 (8), 212 (4), 168 (2), 140 (4), 94 (2), 57(100). Anal. calc. for
2
+
C H O (338.32): C 56.80, H 5.36; found: C 56.72, H 5.39.
A
H
R
U
G
16
18
8
Tetraethyl Benzene-1,2,3,5-tetracarboxylate (1d). Yield: 0.28 g (39%). Colorless powder. M.p.
1
3
7
4–768. IR (KBr): 1716, 1719, 1724 (4 C=O); 1454; 1244. H-NMR: 1.26 (t, J=7.1, Me); 1.40 (t,
3
3
3
3
J=7.2, 2 Me); 1.45 (t, J=7.2, Me); 4.34 (q, J=7.1, CH O); 4.41 (q, J=7.2, 2 CH O); 4.46 (q,
2
2
3
13
J=7.2, CH O); 8.80 (s, 2 CH). C-NMR: 13.9 (Me); 14.1 (2 Me); 14.3 (Me); 62.0 (CH O); 62.1 (C);
2
2
6
2.2 (2 CH O); 129.7(C); 131.4 (C); 134.8 (2 CH); 140.2 (C); 164.2, 164.4, 16 7. 4 (4 C =O). EI-MS: 257
2
+
(
3, M ), 212 (4), 226 (6), 154 (8), 126 (84), 82 (18), 59 (100). Anal. calc. for C H O (366.37): C 59.01,
A
H
R
N
18
22
8
H 6.05; found: C 58.94, H 6.01.
1
X-Ray Crystal-Structure of 1b ). Structure-determination and refinement data: C H O , M 338.30,
16
18
8
r
crystal size 0.220.200.05 mm, monoclinic, a=9.1177(6), b=9.7933(7), c=26.7605(18) ; a=90,
3
À3
b=92.635(5), g=908; space group C 2/c, Z=8, V=3331.7(10) , D =1.349 g cm ; R=0.0845,
calc.
R
w
a
=0.1354; À31ꢀhꢀ32; À13ꢀkꢀ14; À18ꢀlꢀ20; MoK radiation (l=0.71073 ); T=120(2) K.
REFERENCES
[1] R. Cao, Q. Shi, D. Sun, M. Hong, W. Bi, Y. Zhao, Inorg. Chem. 2002, 41, 6161.
[2] Q. Shi, R. Cao, D.-F. Sun, M.-C. Hong, Y.-C. Liang, Polyhedron 2001, 20, 3287.
[3] Y. Li, N. Hao, Y. Lu, E. Wang, Z. Kang, C. Hu, Inorg. Chem. 2003, 42, 3119; Y. Li, H. Zhang, E. Wang,
N. Hao, Ch. Hu, Y. Yan, D. Hall, New J. Chem. 2002, 26, 1619.
[
[
4] J. I. Dickstein, S. I. Miller, in ꢁThe Chemistry of Carbon–Carbon Triple Bonds: Parts 1 and 2ꢂ, Ed. S.
Patai, J. Wiley & Sons, New York, 1978, Chapt. 19.
5] I. Yavari, L. Moradi, Helv. Chim. Acta. 2006, 89, 1942; I. Yavari, L. Moradi, Tetrahedron Lett. 2006,
47, 1627; I. Yavari, Z. Hossaini, M. Sabbaghan, Tetrahedron Lett. 2006, 47, 6037; I. Yavari, Z. Hos-
saini, Tetrahedron Lett. 2006, 47, 4465; I. Yavari, H. Djahaniani, Tetrahedron Lett. 2005, 46, 7491;
I. Yavari, H. Djahaniani, F. Nasiri, Synthesis 2004, 679; I. Yavari, F. Nasiri, H. Djahaniani, Mol.
Divers. 2004, 8, 431; I. Yavari, F. Nasiri, L. Moradi, H. Djahaniani, Tetrahedron Lett. 2004, 45, 7099.
6] A. M. N. Burnett, C. K. Johnson, ꢁOak Ridge National Laboratory Report ORNL-6895ꢂ, 1996.
7] V. Nair, C. Rajesh, A. U. Vinod, S. Bindu, A. R. Sreekanth, J. S. Mathess, L. Balagopal, Acc. Chem.
Res. 2003, 36, 899.
[
[
Received July 23, 2006
1)
The crystallographic data of 1b have been deposited with the Cambridge Crystallographic Data Cen-
tre as supplementary publication number CCDC-299058. Copies of the data can be obtained, free of
charge, at http://www.ccdc.cam.ac.uk/data_request/cif.