2380
M. del Carmen Cruz, J. Tamariz / Tetrahedron Letters 45 (2004) 2377–2380
ꢀ
7. Herrera, R.; Jimenez-Vazquez, H. A.; Modelli, A.; Jones,
D.; Soderberg, B. C.; Tamariz, J. Eur. J. Org. Chem. 2001,
ꢀ
acetic acid as a pale brown solid: Rf 0.38 (hexane/EtOAc/
AcOH, 2:3:0.1); mp 114–115 °C; IR (CH2Cl2) 3502–2340,
1734, 1599, 1509, 1458, 1436, 1281, 1261, 1225, 1203, 1164,
.
1082, 1024, 930, 826, 767 cmꢀ1 1H NMR (300 MHz,
€
4657–4669.
8. Reyes, A.; Aguilar, R.; Munoz, A. H.; Zwick, J.-C.;
~
Rubio, M.; Escobar, J.-L.; Soriano, M.; Toscano, R.;
Tamariz, J. J. Org. Chem. 1990, 55, 1024–1034, and
references included therein.
CDCl3) d 3.81 (s, 3H, CO2Me), 3.82 (s, 3H, OMe), 4.62 (s,
3H, CH2O), 6.33 (dd, J ¼ 8:5, 2.7 Hz, 1H, ArH), 6.58 (d,
J ¼ 2:7 Hz, 1H, ArH), 6.74 (d, J ¼ 8:5 Hz, 1H, ArH),
10.30 (br s, 1H, CO2H); 13C NMR (75.4 MHz, CDCl3) d
55.8 (MeO), 56.2 (MeO), 65.3 (CH2O), 101.2 (ArH), 103.5
(ArH), 111.3 (ArH), 144.3 (Ar), 149.9 (Ar), 151.9 (Ar),
174.6 (CO2H). Anal. calcd for C10H12O5: C, 56.60; H,
5.70. Found: C, 56.64; H, 5.65. A mixture of the
phenoxyacetic acid (1.0 g, 4.7 mmol) and p-toluenesulfonic
acid (0.1 g, 0.53 mmol) in drymethanol (5 mL) was stirred
at room temperature for 2 h. The solvent was removed
under vacuum. The residue was dissolved in EtOAc (5 mL)
and washed with saturated solution of NaHCO3 until
neutral. The organic layer was dried (Na2SO4) and the
solvent was removed. The residue was purified bycolumn
chromatographyon silica gel (15 g, hexane/EtOAc, 9:1), to
give 0.9 g (84%) of 9d as a white solid (hexane/EtOAc, 6:4):
Rf 0.72 (hexane/EtOAc, 6:4); mp 43–44 °C; IR (CH2Cl2)
2947, 1753, 1601, 1509, 1444, 1259, 1222, 1192, 1157, 1080,
ꢀ
ꢀ
9. Jimenez-Vazquez, H. A.; Ochoa, M. E.; Zepeda, G.;
Modelli, A.; Jones, D.; Mendoza, J. A.; Tamariz, J. J.
Phys. Chem. A 1997, 101, 10082–10089.
10. Peralta, J.; Bullock, J. P.; Bates, R. W.; Bott, S.; Zepeda,
G.; Tamariz, J. Tetrahedron 1995, 51, 3979–3996.
11. In particular, enaminones have proved to be privileged
Michael acceptors: (a) Lue, P.; Greenhill, J. V. Enami-
nones in Heterocyclic Synthesis. Adv. Heterocycl. Chem.
1997, 67, 207–343; (b) Elassar, A.-Z. A.; El-Khair, A. A.
Tetrahedron 2003, 59, 8463–8480; (c) Stanovnik, B.; Svete,
J. Synlett 2000, 1077–1091; (d) Greenhill, J. V. Chem. Soc.
Rev. 1977, 6, 277–294.
ꢀ
ꢀ
12. Mendoza, J. A.; Jimenez-Vazquez, H. A.; Herrera, R.;
Liu, J.; Tamariz, J. Rev. Soc. Quꢀım. Mꢀex 2003, 47, 116–
208.
13. Aguilar, J. R. M.Sc. Thesis, Escuela Nacional de Ciencias
1
Biologicas, Instituto Politecnico Nacional, 2000.
14. Typical procedure for preparation of 4d: A mixture of 9d
(0.50 g, 2.21 mmol) and DMFDMA (0.79 g, 6.63 mmol)
was heated to 90 °C for 24 h. The crude mixture was
diluted with CH2Cl2 (20 mL), and the solvent was
removed. The residue was purified bycolumn chromato-
graphyon silica gel (20 g, hexane/EtOAc, 8:2), to give
0.42 g (68%) of 4d as a white solid (hexane/EtOAc, 1:1): Rf
0.20 (hexane/EtOAc, 6:4); mp 81–82 °C; IR (KBr) 1695,
1023, 838, 769 cmꢀ1. H NMR (300 MHz, CDCl3) d 3.77
ꢀ
ꢀ
(s, 3H, CO2Me), 3.79 (s, 3H, OMe), 3.82 (s, 3H, OMe),
4.56 (s, 3H, CH2O), 6.30 (dd, J ¼ 8:7, 2.7 Hz, 1H, ArH),
6.58 (d, J ¼ 2:7 Hz, 1H, ArH), 6.72 (d, J ¼ 8:7 Hz, 1H,
ArH); 13C NMR (75.4 MHz, CDCl3) d 52.1 (CO2CH3),
55.7 (MeO), 56.2 (MeO), 65.8 (CH2O), 101.2 (ArH), 103.4
(ArH), 111.3 (C-2), 144.1 (Ar), 149.8 (Ar), 152.2 (Ar),
169.4 (CO2CH3); MS (70 eV) m=z 226 (Mþ, 100), 211 (55),
183 (16), 153 (64), 137 (10), 125 (47), 110 (21), 95 (16), 79
(30). Anal. calcd for C11H14O5: C, 58.40; H, 6.24. Found:
C, 58.48; H, 6.14.
1633, 1508, 1438, 1299, 1224, 1188, 1120, 1086, 1026 cmꢀ1
.
1H NMR (300 MHz, CDCl3) d 2.93 (s, 6H, N(CH3)2), 3.59
(s, 3H, CO2Me), 3.78 (s, 3H, OMe), 3.81 (s, 3H, OMe),
6.38 (dd, J ¼ 8:7, 2.7 Hz, 1H, ArH), 6.55 (d, J ¼ 2:7 Hz,
1H, ArH), 6.71 (d, J ¼ 8:7 Hz, 1H, ArH), 7.10 (s, 1H,
HC@); 13C NMR (75.4 MHz, CDCl3) d 42.0 (N(CH3)2),
51.1 (CO2CH3), 55.7 (MeO), 56.2 (MeO), 100.1 (ArH),
104.3 (ArH), 111.6 (ArH), 115.0 (OC@), 139.6 (HC@),
143.6 (Ar), 149.7 (Ar), 153.6 (Ar), 166.6 (CO2CH3). Anal.
calcd for C14H19NO5: C, 59.91; H, 6.81. Found: C, 60.02;
H, 6.95.
19. (a) Olah, G. A.; Krishnamurti, R.; Prakash, G. K. S.
Friedel–Crafts Alkylations. In Comprehensive Organic
Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon:
Oxford, 1991; Vol. 3, pp 293–339; (b) Mahindaratne, M.
P. D.; Wimalasena, K. J. Org. Chem. 1998, 63, 2858–
2866.
20. Typical procedure for preparation of 7b: To a solution of
4d (0.05 g, 0.18 mmol) in dryCH 2Cl2 (100 mL) at room
temperature, anhydrous ZnCl2 (0.072 g, 0.53 mmol) was
added. The mixture was stirred at room temperature for
72 h, filtered, and the solvent was removed under vacuum.
The residue was purified bycolumn chromatographyon
silica gel (5 g, hexane/EtOAc, 8:2), to give 0.028 g (68%) of
7b as a white solid: Rf 0.44 (hexane/EtOAc, 7:3); mp 133–
134 °C (hexane/EtOAc, 7:3); IR (KBr) 2951, 2833, 2358,
1723, 1621, 1561, 1489, 1436, 1299, 1221, 1137, 1004, 854,
15. For a related synthesis of 3-dimethylaminopropenoates,
see: (a) Smodis, J.; Stanovnik, B. Tetrahedron 1998, 54,
9799–9810; (b) Selic, L.; Grdadolnik, S. G.; Stanovnik, B.
Helv. Chim. Acta. 1997, 80, 2418–2425.
16. Grdadolnik, S. G.; Stanovnik, B. Magn. Reson. Chem.
1997, 35, 482–486.
~
ꢀ
17. Labarrios, F.; Garduno, L.; Vidal, M. R.; Garcıa, R.;
ꢀ
Salazar, M.; Martınez, E.; Dıaz, F.; Chamorro, G.;
Tamariz, J. J. Pharm. Pharmacol. 1999, 51, 1–7.
762 cmꢀ1 1H NMR (300 MHz, CDCl3) d 3.92 (s, 3H,
.
ꢀ
CO2Me), 3.94 (s, 3H, OMe), 3.95 (s, 3H, OMe), 7.03
(s, 1H, H-7), 7.07 (s, 1H, H-4), 7.44 (s, 1H, H-3);
18. Typical procedure for preparation of 9d: An aqueous
solution (10 mL) of NaOH (3.1 g, 77.5 mmol) and chloro-
acetic acid (4.1 g, 43.4 mmol) in water (10 mL) were
13C NMR (75.4 MHz, CDCl3)
d 52.2 (CO2CH3),
56.23 (MeO), 56.28 (MeO), 95.1 (C-7), 102.5 (C-4),
114.4 (C-3), 118.8 (Ar), 144.4 (Ar), 147.5 (Ar), 151.0
(Ar), 151.2 (Ar), 159.9 (CO2CH3); MS (70 eV) m=z 236
(Mþ, 100), 221 (30), 205 (16), 193 (34), 178 (9), 161 (13),
137 (34), 119 (72), 105 (19), 88 (9), 63 (46). Anal. calcd
for C12H12O5: C, 61.02; H, 5.12. Found: C, 61.07; H,
5.39.
successivelyadded dropwise to phenol
8d (6.0 g,
38.9 mmol) at room temperature. The mixture was stirred
at 60 °C for 7 h. A concentrated aqueous solution of HCl
(36%) was added until pH 2, and the precipitate was
filtered. The solid was recrystallized from hexane/EtOAc
(6:4), giving 6.6 g (80%) of the corresponding phenoxy-