3
3JOCH2,CH3 = 7.1, OCH2); 1.44 (1H, t, JCH3,OCH2 = 7.1, CH3). 13C NMR spectrum (75 MHz, CDCl3): δ, ppm (J, Hz):
3
2
3
164.4 (3JCO,OCH2 = 3.2, JCO,H-2 = 2.2, CO); 151.0 (1J = 181.1, JC-9,H-8 = 3.5, JC-9,H-7 = 7.6, C-9); 150.0 (J = 188.0,
C-2); 147.9 (3JC-4,H-2 = 13.4, 2JC-4,H-5 = 5.8, 3JC-4,H-6 = 1.0, C-4); 145.3 (3JC-10a,H-6 = 6.4, 3JC-10a,H-7 = 5.6, 3JC-10a,H-9 = 10.8,
C-10a); 142.7 (3JC-10b,H-2 = 8.0, JC-10b,H-5 = 5.0, C-10b); 135.9 (J = 163.1, JC-7,H-6 = 4.7, JC-7,H-9 = 5.8, C-7); 129.1
3
3
3
(2JC-6a,H-6 = 2.3, 2JC-6a,H-7 = 1.2, JC-6a,H-5 = 9.5, JC-6a,H-8 = 7.4, C-6a); 128.2 (1J = 162.8, JC-6,H-7 = 5.1, C-6); 126.5
3
3
3
(3JC-4a,H-6 = 9.4, C-4a); 125.1 (2JC-3,H-2 = 8.1, C-3); 124.0 (1J = 164.9, 3JC-8,H-9 = 9.1, C-8); 122.4 (1J = 165.8, C-5); 62.2
(1J = 148.5, JOCH2,CH3 = 4.4, OCH2); 14.1 (1J = 127.4, JCH3,OCH2 = 2.6, CH3). 15N NMR spectrum (50 MHz,
DMSO-d6): δ, ppm: −75.6 (N-10); −82.4 (N-1). Mass spectrum, m/z (Irel, %): 288 [M]+ (22), 286 [M]+ (60), 243 (20),
242 (25), 241 (100), 213 (82), 178 (35), 151 (61), 75 (24).
2
2
4-Chloro-1,10-phenanthroline-3-carboxylic acid (5). Compound 4 (573 mg, 2 mmol) was dissolved in
DME (30 ml), and aqueous KOH (40%, 30 ml) was added. The reaction mixture was stirred overnight. Then, the
formed precipitate was filtered off, treated with 1N HCl, and filtered off again and dried to obtain 358 mg of the
beige mixture of compounds 5 and 6; mp 310–314°C. During the recording of the NMR spectra in DMSO-d6,
1
hydrolysis of compound 5 was observed. Compound 5: H NMR spectrum (500 MHz, DMSO-d6), δ, ppm (J,
Hz): 9.44 (1H, s, H-2), 9.38 (1H, m, H-9), 9.36 (1H, m, H-7), 8.40 (1H, m, H-8), 8.58 (1H, d, 3J5,6 = 9.3, H-5),
3
8.48 (1H, d, J5,6 = 9.3, H-6), 4.82 (1H, br. s, COOH). Mass spectrum, m/z (Irel, %): 260 [M]+ (18), 258 [M]+
(38), 241 (38), 196 (83), 168 (87), 140 (37), 111 (26), 98 (43), 97 (30), 81 (33), 69 (71), 57 (66), 55 (71), 45
(58), 43 (100), 41 (62). HRMS (EI, 70 eV), m/z: Found: 258.0202 [M]+. C13H7ClN2O2. Calculated: 258.0196.
1
Compound 6 [13]: H NMR spectrum (500 MHz, DMSO-d6), δ, ppm (J, Hz): 13.84 (2H, 2s, NH); 9.14
3
4
3
4
(1H, dd, J9,8 = 4.3, J9,7 = 1.6, H-9); 8.73 (1H, s, H-2); 8.62 (1H, dd, J7,8 = 8.3, J7,9 = 1.6, H-7); 8.24 (1H, d,
3J5,6 = 8.9, H-5); 8.03 (1H, d, 3J6,5 = 8.9, H-6); 7.91 (1H, dd, 3J8,7 = 8.3, 3J8,9 = 4.3, H-8); 4.82 (1H, br. s, COOH).
13C NMR spectrum (125 MHz, DMSO-d6), δ, ppm (J, Hz): 177.9 (3JC-4,H-2 = 6.4, JC-4,H-5 = 3.3, C-4); 166.2
3
(3JCO,H-2 = 3.5, CO); 150.7 (1J = 181.7, JC-9,H-8 = 3.6, JC-9,H-7 = 7.6, C-9); 143.8 (1J = 182.8, C-2); 138.4
2
3
(3JC-10a,H-9 = 12.3, JC-10a,H-6 = 6.5, JC-10a,H-7 = 5.8, JC-10a,H-5 = 1.0, C-10a); 137.1 (3JC-10b,H-5 = 7.0, C-10b); 137.0
3
3
4
(1J = 166.6, JC-7,H-9 = 6.1, JC-7,H-6 = 4.5, C-7); 129.7 (2JC-6a,H-6 = 2.4, 3JC-6a,H-5 = 9.6, JC-6a,H-8 = 7.5, C-6a); 125.4
(1J = 167.5, 3JC-6,H-7 = 4.6, C-6); 125.2 (1J = 166.9, 2JC-8,H-9 = 8.9, C-8); 123.6 (3JC-4a,H-6 = 8.8, C-4a); 121.3 (1J = 168.2,
C-5); 110.5 (C-3). 15N NMR spectrum (50 MHz, DMSO-d6), δ, ppm: −83.4 (N-10); −236.9 (N-1).
4-Chloro-1,10-phenanthroline-3-carbonyl chloride (7) [13]. The crude mixture resulting from
saponification of ester 4 (compound 5 or a mixture of compounds 5 and 6) was suspended in SOCl2 (15 ml), and
DMF (3 drops) was added. The reaction mixture was refluxed for 3 h. After cooling to room temperature, the
solvent was evaporated under reduced pressure to give the crude acid chloride 7, which was used in the
following acylation reaction without further purification.
3
3
3
8-Methyl-10-phenylpyrazolo[4',3':5,6]pyrano[3,2-c][1,10]phenanthrolin-7(10H)-one
(10).
Under
stirring, to a suspension of 3-methyl-1-phenyl-2-pyrazolin-5-one (8) (174 mg, 1 mmol) and Ca(OH)2 (148 mg,
2 mmol) in dioxane (1 ml) was added the crude acid chloride 7 (277 mg, 1 mmol) in dioxane (2 ml) and the
mixture was refluxed for 3 h. After cooling to room temperature, 2N HCl (3 ml) and H2O (5 ml) were added.
After 20 h, the precipitate was filtered off and washed with H2O to obtain the target compound 10. An analytical
sample was recrystallized from ethanol and DMF. Yield 151 mg (40%); beige–pale brownish powder;
mp > 340°C. IR spectrum (KBr), ν, cm−1: 1664. 1H NMR spectrum (500 MHz, DMSO-d6): δ, ppm (J, Hz): 9.70
3
4
3
4
(1H, s, H-6); 9.21 (1H, dd, J3,2 = 4.2, J3,1 = 1.4, H-3); 8.63 (1H, dd, J1,2 =8.1, J1,3 = 1.4, H-1); 8.38 (1H, d,
3J12,13 = 9.1, H-12); 8.29 (1H, d, 3J13,12 = 9.1, H-13); 8.04 (2H, m, H-2,6, Ph); 7.89 (1H, dd, 3J2,3 = 4.2, 3J2,1 = 8.1,
H-2); 7.74 (2H, m, H-3,5, Ph); 7.55 (1H, m, H-4, Ph); 2.65 (3H, s, CH3). H NMR spectrum (500 MHz,
pyridine-d5): δ, ppm (J, Hz): 10.30 (1H, s, H-6); 9.36 (1H, dd, J3,2 = 4.1, J3,1 = 1.7, H-3); 8.47 (1H, d,
3J12,13 = 9.0, H-12); 8.33 (1H, dd, 3J1,2 = 8.1, 4J1,3 = 1.7, H-1); 8.23 (2H, m, H-2,6, Ph); 8.06 (1H, d, 3J13,12 = 9.0,
H-13); 7.66 (2H, m, H-3,5, Ph); 7.65 (1H, dd, J2,3 = 4.1, J2,1 = 8.1, H-2); 7.46 (1H, m, H-4, Ph); 2.81 (3H, s,
CH3). 13C NMR spectrum (125 MHz, pyridine-d5): δ, ppm: 172.5 (C-7); 156.8 (C-11a); 151.3 (C-3); 149.2 (C-4b);
1
3
4
3
3
713