3.4. General Procedure for the Synthesis of Metallophthalocyanines 5–7
Compound 3 (0.24 mmol), 0.06 mmol of the corresponding metal salts (ZnCl2, CuCl2•2H2O, CoCl2•6H2O), N,N-dimethylaminoethanol (DMAE) (4 mL) and 1,8-diazabicyclo [4.5.0]-undec-7-ene (DBU) (3 drops) were added in a Schlenk tube. The mixture was heated at reflux temperature of 170 °C for 48 h under a N2 atmosphere. After cooling to room temperature, the precipitate was filtered off and dried in vacuo over P2O5. The obtained green solid product was purified with column chromatography on silica gel with chloroform/methanol (8:1) as eluent.
Co(II)Pc (5).Yield: (52%). m.p. = 330 °C. FT-IR (KBr) νmax, cm−1: 3024 (C-Harom); 1387 (C-C); 1270 (C-N); 1607 (C=C); 1480 (C=N); 902 (Co-N). UV/Vis (DMSO, λmax nm (log ε)): 340 (5.033), 606 (4.648), 693 (5.243). Calc. for (C67H36N8O12Co): calculated (C, 66.83%; H, 3.01%; N, 9.30%); found (C, 66.8%; H, 3.20%; N, 9.4%).
Zn(II)Pc (6). Elution solvent system: chloroform/methanol (100:3) as eluent. Yield: (66%). m.p. = 330 °C. FT-IR (KBr) νmax, cm−1: 3020 (C-Harom); 1390 (C-C); 1272 (C-N); 1602 (C=C); 1482 (C=N); 903 (Zn-N). UV/Vis (DMSO, λmax nm (log ε)): 331 (4.924), 620 (4.653), 690 (5.169). Calc. for (C67H36N8O12Zn): calculated (C, 66.48%; H, 2.99%; N, 9.25%); found (C, 66.5%; H, 3.10%; N, 9.3%).
Cu(II)Pc (7). Yield: (39%). m.p. = 325 °C. FT-IR (KBr) νmax, cm−1: 3020 (C-Harom); 1385 (C-C); 1269 (C-N); 1606 (C=C); 1479 (C=N); 904 (Cu-N). UV/Vis (DMSO, λmax nm (log ε)): 345 (4.818), 622 (4.526), 681 (5.074). Calc. for (C67H36N8O12Cu): calculated (C, 66.58%; H, 3.00%; N, 9.27%); found (C, 66.5%; H, 3.10%; N, 9.3%).
3.5. General Procedure for Preparation of Compounds 8–12
Ethyl acetoacetate (1 mmol), aldehyde (1 mmol) and urea or urea (1.5 mmol) was heated at reflux for appropriate duration of time. After completion of the reaction as indicated by TLC (hexane/ethyl acetate 8:2), the reaction mixture was brought to room temperature. The remaining solid material was washed with hot ethyl acetate. The filtrate was concentrated and the solid product was recrystallized from ethanol to give the pure product.
6-Methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5–carboxylate (8). Yield: (78%). m.p. = 310 °C. IR (KBr): νmax (cm−1) = 3394 (NH); 3217 (NH); 3068 (NH); 1730 (C=O); 1660 (C=O); 1566 (C=C). 1H-NMR δ ppm: 1.06 (t, 3H, CH3(a)); 2.24 (s, 3H, CH3(b)); 3.85 (q, 2H, Hd); 6.74 (s, 1H, H3); 6.87 (s, 1H, H1); 7.1 (s, 1H, H6); 13C-NMR δ ppm: 13.5 (CH3(b)); 16.6 (CH3(a)); 52.5 (Cb); 60.7 (Cd); 109.8 (C5); 141.6 (C4); 158.7 (CO ester); 157.4 (C2), 127.4–144.2(Carom). Calc. for C14H1503N2 C, 9.82%; H, 88.53%, N, 1.63%; found: C 9.7%; H, 88.4%; N, 1.5%.
4-(3-Methoxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5–carboxylate (9). Yield: (92%). M.p. = 220 °C. IR (KBr): νmax (cm−1) = 3361 (NH); 3221 (NH); 1725 (C=O); 1616 (C=O); 1581 (C=C). 1H-NMR δ ppm: 1.14 (s,3H, (CH3(b)); 1.2 (s, 3H, (CH3(c)); 2,19 (s, 3H, CH3(a)); 4.50 (s, 2H, Hd); 6.72 (s, 1H, H3); 7.3-8.4 (m, 5H, Harom); 5.24 (s, 1H, H6). 13C-NMR δ ppm: 13.6 (CH3); 16.5 (CH3(b)); 42.1 (CH3(a)); 52.4 (C6); 60.6 (Cd); 109.6 (C5); 140.7 (C4); 159.6 (COester); 163,5 (C1); 127.5–139.4 (Carom), 176,4 (C3). Calc. for C15H1704N2 C, 9.35%; H, 89.19%, N, 1.45%; found: C, 9.4%; H, 89.2%; N, 1.5%.
4-(3-Methylphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5–carboxylate (10). Yield: (96%). M.p. = 315 °C. IR (KBr): νmax (cm−1) = 3382 (NH); 3232 (NH); 1720 (C=O); 1652 (C=O); 1570 (C=C). 1H-NMR δ ppm: 1.03 (t, 3H, CH3(c)); 2.24 (s, 3H, CH3(b)); 3.42 (s, 3H, CH3(a)); 3.82 (q, 2H, Hd); 5.85 (s, 1H, Hb); 6,85 (dd, 1H, H6′); 6.80 (s, 1H, H2′); 7.1 (dd, 1H, H4′); 7.25 (dd, 1H, H5′); 7.6 (s, 1H, H1); 8.7 (s, 1H, H3). 13C-NMR δ ppm: 55.5 (OCH3); 16.4 (CH3(b)); 42.5 (CH3(a)); 52.7 (C6); 60,4 (Cd); 109.5 (C5); 140.6 (C4); 160.1 (COester); 156.5 (C2); 127.3–139.1 (Carom). Calc. for C15H1703N2 C, 9.36%; H, 89.18%, N, 1.45%; found: C, 9.4%; H, 89.2%; N, 1.5%.
4-(4-Bromophenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5–carboxylate (11). Yield: (92%). m.p. = 315 °C. IR (KBr): νmax (cm−1) = 3398 (NH); 3219 (NH); 3107 (NH); 1720 (C=O); 1631 (C=O); 1568 (C=C). 1H-NMR δ ppm: 1.4 (t, 3H, CH3(c)); 2.22 (s, 3H, CH3(b)); 2.14 (s, 6H, N(CH3)2); 3.55 (q, 2H, Hd); 5.85 (s, 1H, H6); 8.65 (s, 1H, H3); 7.40 (s, 1H, H1); 6.62–7.25 (m, 5H, Harom). 13C-NMR δ ppm: 16.5 (N(CH3)2); 14.6 (CH3(b)); 42.5 (CH3(a)); 52.7 (C6); 61.1 (Cd); 109.4 (C5); 141.3 (C4); 158.8 (COester); 157.4(C2); 125.5–137.3 (Carom). Calc. for C14H1403N2Br C, 9.948%; H, 83.66%, N, 1.65%; found: C, 9.8; H, 83.2, N, 1.7.
4-(4-Nitrophenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5–carboxylate (12). Yield: (85%). m.p. = 315 °C. IR (KBr): νmax (cm−1) = 3390.6 (NH); 3218 (NH); 1729 (C=O); 1656 (C=O); 1560.3 (C=C). 1H-NMR δ ppm: 1.3 (t, 3H, CH3(c)); 2.22 (s, 3H, CH3(b)); 3.85 (q, 2H, Hd); 5.98 (s, 1H, H6); 8.69 (s, 1H, H3); 7.50 (s, 1H, H1); 6.76–7.36 (m,5H, Harom). 13C-NMR δ ppm: 14.9 (CH3(b)); 41.5 (CH3(a)); 53.7 (C6); 61.3 (Cd); 108.2 (C5); 142.3 (C4); 158.6 (COester); 157. 4 (C2); 127.5-139.3 (Carom). Calc. for C14H14O5N3 C, 10.33%; H, 87.07%; N, 2.58%; found: C, 10.4%; H, 87.2%; N, 2.6%.