Synlett 2004(1): 61-64  
DOI: 10.1055/s-2003-43350
LETTER
© Georg Thieme Verlag Stuttgart · New York

Highly Efficient Mechanochemical Reactions of 1,3-Dicarbonyl Compounds with Chalcones and Azachalcones Catalyzed by Potassium Carbonate

Ze Zhanga, Ya-Wei Donga, Guan-Wu Wang*a, Koichi Komatsub
a Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
Fax: +86(551)3607864; e-Mail: gwang@ustc.edu.cn;
b Institute for Chemical Research, Kyoto University, Uji, Kyoto 611, Japan
Further Information

Publication History

Received 19 September 2003
Publication Date:
26 November 2003 (online)

Abstract

Under the high-speed vibration milling conditions, K2CO3 was found to be a very efficient catalyst for the solvent-free Michael reactions of 1,3-dicarbonyl compounds with chalcones and azachalcones. In most cases, conventional side reactions were avoided and thus excellent yields were achieved. The influences of other catalysts and the vibration frequency on the Michael reaction were investigated.

16

General Procedure for the Synthesis of Compounds 3:
A mixture of compound 1 (0.1 mmol), diethyl malonate 2 (15.2 µL, 0.1 mmol) and K2CO3 (1.4 mg, 0.01 mmol) was vigorously shaken by HSVM for a designated time. The reaction mixture was collected and washed with water to remove the small amount of K2CO3, and then dried to give the crude product 3. The obtained product is essentially pure and can be further purified by crystallization from petroleum ether-EtOAc (10:1) at -20 ºC. Products 3c, 3i and 3m were purified by column chromatography on silica gel with petroleum ether-EtOAc (5:1) as an eluent.
Selected analytical data:3f: Mp 93-94 ºC. IR (KBr): 2224, 1752, 1731, 1686 cm-1. 1H NMR (300 MHz, CDCl3): δ = 7.87 (d, J = 7.6 Hz, 2 H), 7.54 (d, J = 8.0 Hz, 2 H), 7.53 (m, 1 H), 7.43 (d, J = 7.6 Hz, 2 H), 7.41 (d, J = 8.0 Hz, 2 H), 4.26-4.14 (m, 3 H), 3.98 (q, J = 7.1 Hz, 2 H), 3.81 (d, J = 9.5 Hz, 1 H), 3.57 (dd, J = 17.3, 4.6 Hz, 1 H), 3.48 (dd, J = 17.3, 9.2 Hz, 1 H), 1.23 (t, J = 7.1 Hz, 3 H), 1.04 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3) δ = 196.90, 167.92, 167.42, 146.41, 136.51, 133.50, 132.26 (2 × C), 129.39 (2 × C), 128.78 (2 × C), 128.10 (2 × C), 118.74, 111.15, 62.02, 61.74, 56.91, 42.08, 40.68, 14.10, 13.90. HRMS (EI-TOF): m/z [M+] calcd for C23H23NO5: 393.1576; found: 393.1577.
3h: Mp 114-115 ºC. IR (KBr): 1743, 1721, 1684 cm-1. 1H NMR (300 MHz, CDCl3): δ = 7.90 (dd, J = 7.8, 1.3 Hz, 2 H), 7.56 (t, J = 7.3 Hz, 1 H), 7.44 (t, J = 7.5 Hz, 2 H), 7.38 (d, J = 2.0 Hz, 1 H), 7.32 (d, J = 8.3 Hz, 1 H), 7.16 (dd, J = 8.3, 2.0 Hz, 1 H), 4.26-4.11 (m, 3 H), 4.02 (q, J = 7.1 Hz, 2 H), 3.77 (d, J = 9.3 Hz, 1 H), 3.55 (dd, J = 17.2, 4.6 Hz, 1 H), 3.44 (dd, J = 17.2, 9.2 Hz, 1 H),1.25 (t, J = 7.1 Hz, 3 H), 1.09 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 197.04, 168.07, 167.55, 141.13, 136.62, 133.48, 132.47, 131.30, 130.45 (2 × C), 128.81 (2 C), 128.18 (2 × C), 128.06, 62.01, 61.79, 57.15, 42.18, 39.87, 14.15, 13.97. HRMS (EI-TOF): m/z [M+] calcd for C22H22O5 35Cl2: 436.0844; found: 436.0847.
3i: Mp 58-60 ºC. IR (KBr): 1748, 1728, 1682 cm-1. 1H NMR (300 MHz, CDCl3) δ = 7.90 (dd, J = 7.4, 1.2 Hz, 2 H), 7.54 (t, J = 7.3 Hz, 1 H), 7.43 (t, J = 7.6 Hz, 2 H), 6.76 (d, J = 1.1 Hz, 1 H), 6.71 (dd, J = 8.0, 1.1 Hz, 2 H), 6.66 (d, J = 8.0 Hz, 1 H), 5.88 (s, 2 H), 4.20 (qd, J = 7.1, 2.6 Hz, 2 H), 4.10 (td, J = 9.4, 4.7 Hz, 1 H), 4.01 (q, J = 7.1 Hz, 2 H), 3.75 (d, J = 9.8 Hz, 1 H), 3.50 (dd, J = 16.5, 4.6 Hz, 1 H), 3.39 (dd, J = 16.5, 9.3 Hz, 1 H), 1.25 (t, J = 7.1 Hz, 3 H), 1.08 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 197.70, 168.45, 167.83, 147.67, 146.65, 136.95, 134.32, 133.20, 128.71 (2 × C), 128.26 (2 × C), 121.65, 108.78, 108.27, 101.06, 61.81, 61.53, 57.90, 42.88, 40.75, 14.18, 14.01. HRMS (EI-TOF): m/z [M+] calcd for C23H24O7: 412.1522; found: 412.1527.
3j: Mp 66-67 ºC. IR (KBr): 1749, 1730, 1699, 1521, 1348 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.64 (d, J = 4.2 Hz, 1 H), 8.11 (d, J = 8.6 Hz, 2 H), 7.90 (d, J = 7.8 Hz, 1 H), 7.78 (td, J = 7.6, 1.6 Hz, 1 H), 7.53 (d, J = 8.6 Hz, 2 H), 7.45 (dd, J = 7.0, 4.6 Hz, 1 H), 4.32 (td, J = 10.0, 4.0Hz, 1 H), 4.21 (qd, J = 7.1, 2.5 Hz, 2 H), 3.97 (q, J = 7.1 Hz, 2 H), 3.97 (dd, J = 18.2, 9.9 Hz, 1 H), 3.85 (d, J = 10.2 Hz, 1 H), 3.64 (dd, J = 18.2, 4.1 Hz, 1 H), 1.26 (t, J = 7.1 Hz, 3 H), 1.04 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 198.52, 167.80, 167.45, 152.88, 149.08, 148.93, 147.05, 137.13, 129.69 (2 × C), 127.62, 123.64 (2 × C), 121.96, 62.09, 61.76, 57.22, 41.67, 40.24, 14.17, 13.98. HRMS (EI-TOF): m/z [M+] calcd for C21H22N2O7: 414.1427; found: 414.1424.
3k: Mp 72-74 ºC. IR (KBr): 1748, 1729, 1691, 1531, 1352 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.65 (d, J = 4.3 Hz, 1 H), 8.22 (s, 1 H), 8.03 (dd, J = 7.7, 1.7 Hz, 1 H), 7.90 (d,
J = 7.9 Hz, 1 H), 7.79 (dd, J = 7.4, 1.2 Hz, 1 H), 7.73 (d, J = 8.7 Hz, 1 H), 7.46 (d, J = 5.0 Hz, 1 H), 7.41 (d, J = 8.1 Hz, 1 H), 4.3 2 (td, J = 9.8, 4.1 Hz, 1 H), 4.21 (q, J = 7.1 Hz, 2 H), 3.97 (dd, J = 18.2, 9.9 Hz, 1 H), 3.97 (q, J = 7.1 Hz, 2 H), 3.85 (d, J = 10.1 Hz, 1 H), 3.66 (dd, J = 18.2, 4.0 Hz, 1 H), 1.25 (t, J = 7.1 Hz, 3 H), 1.03 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 198.61, 167.84, 167.49, 152.92, 149.10, 148.28, 143.36, 137.07, 135.44, 129.29, 127.56, 123.43, 122.29, 121.91, 62.04, 61.71, 57.34, 41.61, 40.11, 14.15, 13.94. HRMS (EI-TOF): m/z [M+] calcd for C21H22N2O7: 414.1427; found: 414.1428.
3l: Mp 42-44 ºC. IR (KBr): 2228, 1750, 1732, 1700 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.64 (d, J = 4.6 Hz, 1 H), 7.91 (d, J = 7.8 Hz, 1 H), 7.78 (td, J = 7.6, 1.6 Hz, 1 H), 7.55 (d, J = 8.3 Hz, 2 H), 7.47 (d, J = 8.3 Hz, 2 H), 7.46 (m, 1 H), 4.29-4.16 (m, 3 H), 3.96 (q, J = 7.1 Hz, 2 H), 3.96 (dd, J = 18.2, 9.9 Hz, 1 H), 3.82 (d, J = 10.3 Hz, 1 H), 3.62 (dd, J = 18.2, 4.0 Hz, 1 H), 1.25 (t, J = 7.1 Hz, 3 H), 1.03 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 198.57, 167.82, 167.47, 153.00, 149.04, 146.84, 137.06, 132.18 (2 × C), 129.59 (2 × C), 127.50, 121.91, 118.81, 111.07, 61.98, 61.64, 57.24, 41.56, 40.53, 14.13, 13.92. HRMS (EI-TOF): m/z [M+] calcd for C22H22N2O5: 394.1529; found: 394.1528.
3m: Mp 50-52 ºC. IR (KBr): 1750, 1730, 1697 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.64 (d, J = 4.4 Hz, 1 H), 7.91 (d, J = 7.7 Hz, 1 H), 7.77 (t, J = 7.6 Hz, 1 H), 7.44 (dd, J = 7.0, 5.2 Hz, 1 H), 7.27 (d, J = 8.3 Hz, 2 H), 7.20 (d, J = 8.3 Hz, 2 H), 4.23-4.15 (m, 3 H), 3.95 (q, J = 7.1 Hz, 2 H), 3.90 (dd, J = 17.9, 9.8 Hz, 1 H), 3.78 (d, J = 10.3 Hz, 1 H), 3.57 (dd, J = 17.9, 4.0 Hz, 1 H), 1.25 (t, J = 7.1 Hz, 3 H), 1.03 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 198.84, 168.14, 167.73, 153.16, 148.99, 139.59, 137.01, 132.84, 130.02 (2 × C), 128.55 (2 × C), 127.37, 121.93, 61.84, 61.52, 57.73, 41.87, 39.92, 14.16, 13.93. HRMS (EI-TOF): m/z [M+] calcd for C21H22NO5 35Cl: 403.1187; found: 403.1184. HRMS (EI-TOF): m/z [M+] calcd for C21H22NO5 37Cl: 405.1157; found: 405.1147.
3n: Mp 72-73 ºC. IR (KBr): 1755, 1731, 1695 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.65 (d, J = 4.4 Hz, 1 H), 7.93 (d, J = 7.4 Hz, 1 H), 7.79 (td, J = 7.6, 1.6 Hz, 1 H), 7.45 (m, 1 H), 7.43 (d, J = 2.0 Hz, 1 H), 7.30 (t, J = 8.3 Hz, 1 H), 7.20 (dd, J = 8.3, 2.0 Hz, 1 H), 4.25-4.13 (m, 3 H), 4.00 (q, J = 7.1 Hz, 1 H), 3.90 (dd, J = 18.2, 9.7 Hz, 1 H), 3.77 (d, J = 10.2 Hz, 1 H), 3.58 (dd, J = 18.2, 4.1 Hz, 1 H), 1.25 (t, J = 7.1 Hz, 3 H), 1.06 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 198.61, 167.92, 167.54, 152.98, 149.02, 141.43, 137.06, 132.31, 131.09, 130.66, 130.31, 128.19, 127.49, 121.94, 61.94, 61.66, 57.42, 41.62, 39.63, 14.14, 13.94. HRMS (EI-TOF): m/z [M+] calcd for C21H21NO5 35Cl2: 437.0797; found: 437.0791. HRMS (EI-TOF): m/z [M+] calcd C21H21NO5 35Cl37Cl: 439.0767; found: 439.0744.
3o: Mp 104-105 ºC. IR (KBr): 1743, 1726, 1697 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.65 (d, J = 4.3 Hz, 1 H), 7.92 (d, J = 7.8 Hz, 1 H), 7.77 (td, J = 7.6, 1.4 Hz, 1 H), 7.42 (m, 1 H), 6.81 (d, J = 1.3 Hz, 1 H), 6.77 (dd, J = 7.9, 1.6 Hz, 1 H), 6.66 (d, J = 7.9 Hz, 1 H), 5.87 (s, 2 H), 4.23-4.10 (m, 3 H), 3.98 (q, J = 7.2 Hz, 2 H), 3.87 (dd, J = 17.7, 9.7 Hz, 1 H), 3.74 (d, J = 10.4 Hz, 1 H), 3.53 (dd, J = 17.7, 4.2 Hz, 1 H), 1.24 (t, J = 7.2 Hz, 1 H), 1.06 (t, J = 7.2 Hz, 1 H). 13C NMR (75 MHz, CDCl3): δ = 199.02, 168.31, 167.87, 153.27, 148.97, 147.53, 146.48, 136.96, 134.75, 127.27, 121.94, 121.82, 108.96, 108.17, 100.98, 61.74, 61.42, 58.16, 42.09, 40.25, 14.17, 14.00. HRMS (EI-TOF): m/z [M+] calcd for C22H23NO7: 413.1475; found: 413.1477.