3.2. Synthesis of the Novel Derivatives
3.2.1. Synthesis of 9-Chloroacridine Cores
Synthesis of the substituted or unsubstituted acridine cores passes through an Ullman coupling between the 2-chlorobenzoic acid and amines, forming
N-phenylanthranilinic acids, which undergo an intramolecular cyclization with polyphosphoric acid (PPA), yielding acridones, and finally the chlorination process, forming 9-chloro acridines. A solution of
o-chlorobenzoic acid (6.0 mmol), aniline derivative (12.0 mmol), copper powder (0.6 mmol) and potassium carbonate (12.0 mmol) in DMF (20 mL) was heated under reflux for 8 h. After completion of the reaction (monitored by TLC), the reaction mixture was cooled down to room temperature, poured into hot water and boiled in the presence of activated charcoal for 15 min. Then, it was filtered through celite, and the filtrate was acidified with HCl to obtain a precipitated product that was purified using recrystallization from ethanol to obtain pure products (55–75%). After, a mixture of appropriate
N-phenylanthranilinic acids (2 mmol) and polyphosphoric acid (20 mmol) was heated at 100 °C for 3 h. Upon completion, the reaction mixture was poured into hot water (100 mL). After cooling to room temperature, the mixture was made alkaline by ammonia solution. The obtained yellow precipitates (acridones) were filtered off, washed with hot water and purified using recrystallization from acetic acid to obtain the pure products (70–80%) [
95]. Lastly, a suspension of acridone (5 mmol) in SOCl
2 (6 mL) containing DMF (two drops) was stirred at reflux for 2 h. The solution was evaporated in vacuo, and residual traces of SOCl
2 were removed by the addition of dry CH
2Cl
2 and complete evaporation of all solvents to give the crude product as a yellow powder, with no need for purification (70–85%) [
63].
Friedel–Crafts acylation reactions were also conducted using phosphoryl chloride (POCl
3) for the synthesis of the corresponding acridine cores. The
N-phenylanthranilinic acid derivatives (5 mmol) were cyclized intramolecularly to 9-chloroacridine derivatives by refluxing them in 5 mL of POCl
3 for 4 h and the reaction was monitored by TLC. After completion, the excess POCl
3 was removed by a rotary evaporator under reduced pressure. To the crude reaction mass, crushed ice was added, and pH was adjusted to ~7 by adding saturated bicarbonate solution. The separated solid was filtered, dried and purified by flash column chromatography with silica gel (60–120 mesh size) using 5–10% hexane:ethyl acetate as eluent to obtain the corresponding 9-chloroacridine derivatives (60–65%) [
39,
40].
3.2.2. Obtaining Thiosemicarbazone Intermediates
Thiosemicarbazone intermediate compounds were obtained by a condensation reaction. In a round-bottom flask, equimolar amounts of thiosemicarbazide (5 mmol) and aldehydes (5 mmol) were mixed in absolute ethanol (20 mL) with a catalytic amount of glacial acetic acid (10 drops). The reaction was initially stirred under gentle heating (40 °C) (10 min), then at room temperature for about 3 h. After reaction completion, the resultant whiteish precipitate was filtered out and then crystallized in EtOH/H
2O [
64].
3.2.3. Obtaining Acridine–Thiosemicarbazone Derivatives (CL 01-10 and DL 01-10)
The synthesis of the new acridine–thiosemicarbazone derivatives was carried out through a condensation reaction with equimolar proportions of thiosemicarbazones and acridines cores as reagents obtained previously. A solution of acridines (1.0 mmol) and thiosemicarbazone intermediates (1.0 mmol) in ethanol (20 mL) was heated under reflux for 1–4 h. Some compounds showed better yields in dioxane, as in the case of hydroxylated compounds. After completion of the reaction, monitored by TLC, the reaction mixture was cooled down to room temperature, filtered, and an amorphous solid (CL1-10 and DL1-10) was obtained, which was crystallized in an EtOH/H
2O system [
50,
51,
52].
3.2.4. (E)-N-(acridin-9-yl)-2-benzylidenehydrazine-1-carbothioamide (CL-01)
Orange solid; yield: 86%. MP: 162–163 °C. Rf 0.50 (n-hexane/ethyl acetate, 6:4). 1H NMR (500 MHz, DMSO): δ ppm 9.39 (s, 1H, NH), 9.28 (s, 1H, NH), 8.58 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.20–8.14 (m, 2H, H-3, H-12), 7.84 (d, J = 4.1 Hz, 4H, H-1, H-2, H-13, H-14), 7.78 (d, J = 7.7 Hz, 2H, H-22, H-26), 7.40–7.28 (m, 3H, H-23, H-24, H-25), 6.98 (s, 1H, H-20). 13C NMR (125 MHz, DMSO-d6): δ ppm: 180.74 (Cq), 144.87 (Cq), 144.42 (CH), 135.22 (CH) 133.80 (Cq), 131.08 (CH), 129.33 (CH), 128.94 (CH), 128.56 (CH), 124.99 (Cq), 124.54 (CH). HPLC purity: 98%. LRMS Exact Mass calcd for C21H16N4S: 356.110; m/z [M]+ found: 357 (100%); 358 (50%); 359 (15%).
3.2.5. (E)-N-(acridin-9-yl)-2-(4-chlorobenzylidene)hydrazine-1-carbothioamide (CL-02)
Orange solid; yield: 81%. MP: 176–177 °C. Rf 0.57 (n-hexane/ethyl acetate, 6:4). 1H NMR (400 MHz, DMSO-d6): δ ppm 9.43 (s, 1H, NH), 9.37 (s, 1H, NH), 8.59 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.18 (dt, J = 8.5, 4.0 Hz, 2H, H-1, H-14), 7.90–7.81 (m, 6H, H-2, H-3, H-12, H-13, H-23, H-25), 7.44–7.36 (m, 2H, H-22, H-26), 7.00 (s, 1H, H-20). 13C NMR (100 MHz, DMSO-d6): δ ppm 180.75 (Cq), 143.18 (CH), 135.59 (Cq), 132.83 (Cq), 130.27 (CH), 129.38 (CH), 129.04 (CH), 124.94 (Cq), 124.52 (CH). HPLC purity: 99%. LRMS Exact Mass calcd for C21H15ClN4S: 390.071; m/z [M]+ found: 391 (100%); 392 (38%); 393 (60%).
3.2.6. (E)-N-(acridin-9-yl)-2-(4-methoxybenzylidene)hydrazine-1-carbothioamide (CL-03)
Orange solid; yield: 91%. MP: 169–170 °C. Rf 0.46 (n-hexane/ethyl acetate, 6:4). 1H NMR (400 MHz, DMSO-d6): δ ppm: 9.33 (s, 1H, NH), 9.26 (s, 1H, NH), 8.61 (d, J = 8.9 Hz, 2H, H-11, H-4), 8.19 (ddd, J = 8.6, 4.7, 3.4 Hz, 2H, H-3, H-12), 7.86 (d, J = 3.6 Hz, 4H, H-1, H-4, H-13, H-14), 7.74 (d, J = 8.9 Hz, 2H, H-22, H-26), 6.95 (s, 1H, H-20), 6.88 (d, J = 9.0 Hz, 2H, H-23, H-25). 13C NMR (100 MHz, DMSO-d6): δ ppm 180.46 (Cq), 161.72 (Cq), 144.47 (CH), 135.45 (Cq), 130.38 (CH), 129.35 (CH), 126.39 (Cq), 125.15 (Cq), 124.70 (CH), 114.42 (CH), 55.79 (OCH3). HPLC purity: 99%. LRMS Exact Mass calcd for C22H18N4OS: 386.120; m/z [M]+ found: 387 (100%); 388 (40%); 389 (14%).
3.2.7. (E)-N-(acridin-9-yl)-2-(2,4-dichlorobenzylidene)hydrazine-1-carbothioamide (CL-04)
Mustard yellow solid; yield: 77%. MP: 172–173 °C. Rf 0.46 (n-hexane/ethyl acetate, 7:3). 1H NMR (400 MHz, DMSO-d6): δ ppm 9.49 (s, 1H, NH), 9.37 (s, 1H, NH), 8.72 (d, J = 8.72, 1H, H-26), 8.46 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.08 (ddd, J = 8.72, 5.5, 2.5 Hz, 2H, H-3, H-12), 7.82–7.79 (m, 4H, H-1, H-4, H-13, H-14), 7.51 (d, J = 8.2 Hz, 2H, H-23, H-25), 6.89 (s, 1H, H-20). 13C NMR (100 MHz, DMSO-d6): δ ppm 181.08 (Cq), 147.02 (Cq), 138.19 (CH), 136.18 (Cq), 134.55 (Cq), 133.67 (CH), 130.15 (CH), 129.84 (Cq), 129.59 (CH), 129.14 (CH), 128.27 (CH), 124.13 (Cq), 124.01 (CH). HPLC purity: 99%. LRMS Exact Mass calcd for C21H14Cl2N4S: 424.032; m/z [M]+ found: 425 (100%); 426 (34%); 427 (83%); 428 (20%).
3.2.8. (E)-N-(acridin-9-yl)-2-(4-nitrobenzylidene)hydrazine-1-carbothioamide (CL-05)
Mustard yellow solid; yield: 78%. MP: 189 °C. Rf 0.50 (n-hexane/ethyl acetate, 6:4). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.53 (s, 1H, NH), 9.46 (s, 1H, NH), 8.53 (d, J = 8.9 Hz, 2H, H-11, H-4), 8.17–8.11 (m, 4H, H-3, H-12, H-23, H-25), 8.09 (d, J = 8.7 Hz, 2H, H-22, H-26), 7.81 (d, J = 4.0 Hz, 4H, H-1, H-2, H-13, H-14), 7.09 (s, 1H, H-20). 13C NMR (125 MHz, DMSO-d6): δ ppm 181.11 (Cq), 148.49 (Cq), 141.79 (CH), 140.20 (Cq), 129.52 (CH), 129.21 (CH), 124.63 (Cq), 124.23 (CH), 124.04 (CH). HPLC purity: 99%. LRMS Exact Mass calcd for C21H15Cl2N5O2S: 401.095; m/z [M]+ found: 402 (100%); 403 (46%).
3.2.9. (E)-N-(acridin-9-yl)-2-(4-methylbenzylidene)hydrazine-1-carbothioamide (CL-06)
Orange solid; yield: 90%. MP: 170–171 °C. Rf 0.45 (n-hexane/ethyl acetate, 6:4). 1H NMR (400 MHz, DMSO-d6): δ ppm 9.36 (s, 1H, NH), 9.26 (s, 1H, NH), 8.57 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.17 (dt, J = 8.5, 4.0 Hz, 2H, H-3, H-12), 7.85 (d, J = 4.0 Hz, 4H, H-1, H-2, H-13, H-14), 7.68 (d, J = 8.2 Hz, 2H, H-22, H-26), 7.14 (d, J = 8.0 Hz, 2H, H-23, H-25), 6.94 (s, 1H, H-20), 2.28 (s, 3H, CH3). 13C NMR (100 MHz, DMSO-d6): δ ppm 180.63 (Cq), 144.51 (CH), 141.06 (Cq), 135.21 (CH), 131.12 (Cq), 129.56 (CH), 129.31 (CH), 128.58 (CH), 125.04 (Cq), 124.58 (CH), 21.51 (CH3). HPLC purity: 99%. LRMS Exact Mass calcd for C21H15Cl2N5O2S: 370.125; m/z [M]+ found: 371 (100%); 372 (60%); 373 (15%).
3.2.10. (E)-N-(acridin-9-yl)-2-(4-hydroxybenzylidene)hydrazine-1-carbothioamide (CL-07)
Orange solid; yield: 91%. MP: 183–184 °C. Rf 0.43 (n-hexane/ethyl acetate, 5:5). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.26 (s, 1H, NH), 9.16 (s, 1H, NH), 8.56 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.21–8.12 (m, 2H, H-1, H-14), 7.84 (d, J = 3.8 Hz, 4H, H-2, H-3, H-12, H-13), 7.60 (d, J = 8.8 Hz, 2H, H-22, H-26), 6.87 (s, 1H, H-20), 6.69 (d, J = 8.6 Hz, 2H, H-23, H-25). 13C NMR (125 MHz, DMSO-d6): δ ppm 180.45 (Cq), 160.42 (Cq), 144.66 (CH), 134.93 (CH), 130.48 (CH), 129.16 (CH), 125.09 (Cq), 124.73 (Cq), 124.62 (CH), 115.81 (CH). HPLC purity: 98%. Exact Mass calcd for C21H16N4OS: 372.104; m/z [M]+ found: 373 (100%); 374 (26%).
3.2.11. (E)-N-(acridin-9-yl)-2-(3-hydroxybenzylidene)hydrazine-1-carbothioamide (CL-08)
Rust orange solid; yield: 92%. MP: 145 °C. Rf 0.54 (n-hexane/ethyl acetate, 5:5). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.30 (s, 1H, NH), 9.14 (s, 1H, NH), 8.47 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.09 (d, J = 8.8 Hz, 2H, H-3, H-12), 7.81–7.77 (m, 4H, H-1, H-2, H-13, H-14), 7.16 (d, J = 9.3 Hz, 2H, H-22, H-26), 7.10 (t, J = 7.9 Hz, 1H, H-25), 6.82 (s, 1H, H-20), 6.79 (d, J = 8.2 Hz, 1H, H-24). 13C NMR (125 MHz, DMSO-d6): δ ppm 180.94 (Cq), 157.95 (Cq), 144.30 (CH), 135.07 (Cq), 133.89 (CH), 129.91 (CH), 128.90 (CH), 124.77 (Cq), 124.31 (CH), 119.68 (CH), 118.20 (CH), 114.95 (CH). HPLC purity: 98%. LRMS Exact Mass calcd for C21H16N4OS: 372.104; m/z [M]+ found: 373 (100%); 374 (30%).
3.2.12. (E)-N-(acridin-9-yl)-2-(4-(dimethylamino)benzylidene)hydrazine-1-carbothioamide (CL-09)
Rust orange solid; yield: 88%. MP: 158–159 °C. Rf 0.43 (n-hexane/ethyl acetate, 6:4). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.18 (s, 1H, NH), 9.10 (s, 1H, NH), 8.50 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.11 (d, J = 7.8 Hz, 2H, H-3, H-12), 7.85–7.77 (m, 4H, H-1, H-2, H-13, H-14), 7.57 (d, J = 8.5 Hz, 2H, H-22, H-26), 6.80 (s, 1H, H-20), 6.63 (d, J = 8.5 Hz, 2H, H-23, H-25), 2.92 (s, 6H, N(CH3)2). 13C NMR (125 MHz, DMSO-d6): δ ppm 180.25 (Cq), 144.95 (CH), 134.36 (CH), 130.03 (CH), 128.92 (CH), 125.07 (Cq), 124.61 (CH), 112.03(CH). HPLC purity: 98%. LRMS Exact Mass calcd for C23H21Cl2N5S: 399.152; m/z [M]+ found: 400 (100%); 401 (30%).
3.2.13. (E)-N-(acridin-9-yl)-2-(4-bromobenzylidene)hydrazine-1-carbothioamide (CL-10)
Orange solid; yield: 78%. MP: 178–179 °C. Rf 0.43 (n-hexane/ethyl acetate, 7:3). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.43 (s, 1H, NH), 9.36 (s, 1H, NH), 8.59 (d, J = 8.8 Hz, 2H, H-11, H-4), 8.18 (dt, J = 8.6, 4.0 Hz, 2H, H-3, H-12), 7.85 (d, J = 4.0 Hz, 4H, H-1, H-2, H-13, H-14), 7.78 (d, J = 8.6 Hz, 2H, H-22, H-26), 7.53 (d, J = 8.7 Hz, 2H, H-23, H-25), 6.98 (s, 1H, H-20). 13C NMR (125 MHz, DMSO-d6): δ ppm 180.76 (Cq), 143.29 (CH), 135.19 (CH), 133.17 (Cq), 131.95 (CH), 130.47 (CH), 129.37 (CH), 124.93 (Cq), 124.52 (CH). HPLC purity: 99%. LRMS Exact Mass calcd for C21H15Cl2BrN4S: 434.020; m/z [M]+ found: 435 (100%); 437 (100%).
3.2.14. (E)-2-benzylidene-N-(6-chloro-2-methoxyacridin-9-yl)hydrazine-1-carbothioamide (DL-01)
Orange solid; yield: 74%. MP: 154–155 °C. Rf 0.54 (n-hexane/ethyl acetate, 6:4). 1H NMR (300 MHz, DMSO-d6): δ ppm 9.16 (s, 1H, NH), 9.07 (s, 1H, NH), 8.24 (d, J = 1.7 Hz, 1H, H-11), 8.13 (d, J = 9.4 Hz, 1H, H-4), 7.86–7.80 (m, 2H, H-13, H-14), 7.67–7.54 (m, 3H, H-3, H-22, H-26), 7.33 (dd, J = 9.2, 6.9 Hz, 3H, H-23, H-24, H-25), 6.91 (s, 1H, H-20), 6.78 (d, J = 2.7 Hz, 1H, H-1), 3.82 (s, 3H, OCH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 180.43 (Cq), 158.30 (Cq), 147.37 (Cq), 147.33 (Cq), 142.85 (CH), 138.76, 134.22, 133.44, 131.45, 130.35, 128.42 (CH), 128.11 (CH), 127.75, 126.27, 125.26, 124.98, 122.51, 122.51, 98.57 (CH), 55.67 (OCH3). HPLC purity: 98%. LRMS Exact Mass calcd for C22H17ClN4OS: 420.081; m/z [M]+ found: 421 (100%); 422 (30%); 423 (40%).
3.2.15. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(4-chlorobenzylidene)hydrazine-1-carbothioamide (DL-02)
Orange solid; yield: 80%. MP: 144–145 °C. Rf 0.58 (n-hexane/ethyl acetate, 6:4). 1H NMR (300 MHz, DMSO-d6): δ ppm 9.21 (s, 1H, NH), 9.16 (s, 1H, NH), 8.32 (d, J = 1.8 Hz, 1H, H-11), 8.21 (d, J = 9.6 Hz, 1H, H-4), 7.87 (d, J = 8.3 Hz, 2H, H-22, H-26), 7.72–7.56 (m, 3H, H-3, H-13, H-14), 7.37 (d, J = 8.2 Hz, 2H, H-23, H-25), 6.93 (s, 1H, H-20), 6.78 (d, J = 2.8 Hz, 1H, H-1), 3.82 (s, 3H, OCH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 180.38 (Cq), 158.44 (Cq), 146.42 (Cq), 146.36 (Cq), 141.89 (CH), 139.78, 134.91, 132.44, 130.49, 129.82 (CH), 128.71, 128.47 (CH), 126.96, 126.81, 125.42, 125.12, 122.63, 98.72 (CH), 55.77 (OCH3). HPLC purity: 98%. LRMS Exact Mass calcd for C22H16Cl2N4OS: 454.042; m/z [M]+ found: 455 (100%); 456 (26%); 457 (54%).
3.2.16. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(4-methoxybenzylidene)hydrazine-1-carbothioamide (DL-03)
Orange solid; yield: 88%. MP: 148 °C. Rf 0.46 (n-hexane/ethyl acetate, 6:4). 1H NMR (300 MHz, DMSO-d6): δ ppm 9.16 (s, 1H, NH), 9.08 (s, 1H, NH), 8.39 (d, J = 1.9 Hz, 1H, H-11), 8.28 (d, J = 9.5 Hz, 1H, H-4), 7.79–7.69 (m, 4H, H-3, H-13, H-22, H-26), 7.67 (d, J = 9.1 Hz, 1H, H-14) 6.92 (s, 1H, H-20), 6.89–6.82 (m, 3H, H-1, H-23, H-25), 3.83 (s, 3H, OCH3), 3.73 (s, 3H, OCH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 180.00 (Cq), 161.15 (Cq), 158.55 (Cq), 145.11, 144.94, 143.39 (CH), 141.68, 135.86, 129.90 (CH), 128.97, 127.89, 125.96, 125.82, 125.43, 122.98, 113.91 (CH), 99.08 (CH), 55.86 (OCH3), 55.28 (OCH3). HPLC purity: 99%. LRMS Exact Mass calcd for C23H19ClN4O2S: 450.092; m/z [M]+ found: 451 (100%); 452 (35%); 453 (45%).
3.2.17. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(2,4-dichlorobenzylidene)hydrazine-1-carbothioamide (DL-04)
Orange solid; yield: 80%. MP: 192–193 °C. Rf 0.62 (n-hexane/ethyl acetate, 6:4). 1H NMR (300 MHz, DMSO-d6): 7.54–7.46 (m, 2H), 6.84 (s, 1H), 6.76 (d, J = 2.8 Hz, 1H), 3.84 (s, 3H). δ ppm 9.35 (s, 1H, NH), 9.24 (s, 1H, NH), 8.60 (d, J = 8.6 Hz, 1H, H-26), 8.34 (d, J = 2.2 Hz, 1H, H-11), 8.22 (d, J = 9.5 Hz, 1H, H-4), 7.72–7.62 (m, 2H, H-3, H-13), 7.61 (d, J = 9.3 Hz, 1H, H-14), 7.54–7.46 (m, 2H, H-23, H-25), 6.84 (s, 1H, H-20), 6.76 (d, J = 2.8 Hz, 1H, H-1), 3.84 (s, 3H, OCH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 181.07 (Cq), 159.06 (Cq), 147.89 (Cq), 138.42 (Cq), 137.64 (CH), 136.09 (Cq), 134.85 (Cq), 134.57 (Cq), 132.27, 130.02, 129.82 (Cq), 129.56, 129.29, 128.56, 128.25, 126.99, 125.27, 125.23 (Cq), 122.47 (CH), 98.87 (CH), 56.27 (OCH3). HPLC purity: 99%. LRMS Exact Mass calcd for C22H15Cl3N4OS: 488.003; m/z [M]+ found: 489 (100%); 491 (100%); 492 (20%).
3.2.18. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(4-nitrobenzylidene)hydrazine-1-carbothioamide (DL-05)
Orange solid; yield: 86%. MP: 164–165 °C. Rf 0.61 (n-hexane/ethyl acetate, 7:3). 1H NMR (300 MHz, DMSO-d6): δ ppm 9.32 (s, 1H, NH), 9.26 (s, 1H, NH), 8.29 (d, J = 1.9 Hz, 1H, H-11), 8.18 (d, J = 9.6 Hz, 1H, H-4), 8.13 (s, 4H, H-22, H-23, H-25, H-26), 7.69–7.54 (m, 3H, H-3, H-13, H-14), 7.04 (s, 1H, H-20), 6.75 (d, J = 2.7 Hz, 1H, H-1), 3.82 (s, 3H, OCH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 180.67 (Cq), 158.40 (Cq), 147.88 (Cq), 147.36 (Cq), 140.60, 139.87 (CH), 138.45, 138.11, 134.27, 131.52, 129.07 (CH), 128.58, 127.80, 126.36, 125.10, 124.85, 123.47 (CH), 122.35, 98.45 (CH), 55.72 (OCH3). HPLC purity: 98%. LRMS Exact Mass calcd for C22H16ClN5O3S: 465.066; m/z [M]+ found: 466 (100%); 467 (25%); 468 (42%).
3.2.19. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(4-methylbenzylidene)hydrazine-1-carbothioamide (DL-06)
Orange solid; yield: 90%. MP: 157–158 °C. Rf 0.60 (n-hexane/ethyl acetate, 7:3). 1H NMR (300 MHz, DMSO-d6): δ ppm 9.22 (s, 1H, NH), 9.11 (s, 1H, NH), 8.40 (d, J = 1.9 Hz, 1H, H-11), 8.30 (d, J = 9.5 Hz, 1H, H-4), 7.69 (m, 3H, H-3, H-13, H-14), 7.66 (d, J = 8.9 Hz, 2H, H-22, H-26), 7.12 (d, J = 8.0 Hz, 2H, H-23, H-25), 6.92 (s, 1H, H-20), 6.83 (d, J = 2.7 Hz, 1H, H-1), 3.83 (s, 3H, OCH3), 2.26 (s, 3H, CH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 13C NMR (75 MHz, DMSO) δ 180.14 (Cq), 158.59 (Cq), 145.14 (Cq), 144.99 (CH), 143.52 (Cq), 141.53 (Cq), 140.44 (Cq) 135.86 (Cq), 130.70 (CH), 129.05 (CH), 129.00, 128.14 (CH), 127.91, 125.77 (CH), 125.40, 122.94, 99.01 (CH), 55.88 (OCH3), 21.01 (CH3). HPLC purity: 98%. LRMS Exact Mass calcd for C23H19ClN4OS: 434.097; m/z [M]+ found: 435 (100%); 436 (26%); 437 (34%).
3.2.20. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(4-hydroxybenzylidene)hydrazine-1-carbothioamide (DL-07)
Orange solid; yield: 82%. MP: 163–164 °C. Rf 0.40 (n-hexane/ethyl acetate, 6:4). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.92 (s, 1H, OH), 9.04 (s, 1H, NH), 8.96 (s, 1H, NH), 8.30 (d, J = 2.3 Hz, 1H, H-11), 8.19 (d, J = 9.5 Hz, 1H, H-4), 7.65–7.60 (m, 4H, H-3, H-13, H-22, H-26), 7.58 (d, J = 9.1 Hz, 1H, H-14), 6.76 (d, J = 2.7 Hz, 1H, H-1), 6.71 (s, 1H, H-20), 6.67 (d, J = 8.3 Hz, 2H, H-23, H-25), 3.82 (s, 3H, OCH3). 13C NMR (75 MHz, DMSO-d6): δ ppm 180.54 (Cq), 160.17 (Cq), 158.70 (Cq), 150.14, 148.05 (Cq), 148.00 (Cq), 143.55 (CH), 139.32 (Cq), 134.58 (Cq), 132.20 (CH), 130.52 (CH), 128.85 (CH), 128.48 (CH), 126.65 (CH), 125.85 (Cq), 125.59 (CH), 124.85 (Cq), 123.10 (Cq), 115.75 (CH), 99.14 (CH), 56.15 (OCH3). HPLC purity: 99%. LRMS Exact Mass calcd for C22H17ClN4O2S: 436.076; m/z [M]+ found: 437 (100%); 438 (30%); 439 (45%).
3.2.21. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(3-hydroxybenzylidene)hydrazine-1-carbothioamide (DL-08)
Rust orange solid; yield: 81%. MP: 155 °C. Rf 0.44 (n-hexane/ethyl acetate, 6:4). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.21 (s, 1H, NH), 9.04 (s, 1H, NH), 8.38 (d, J = 2.0 Hz, 1H, H-11), 8.28 (d, J = 9.4 Hz, 1H, H-4), 7.72 (dd, J = 9.0, 2.2 Hz, 2H, H-3, H-13), 7.65 (d, J = 9.2 Hz, 1H, H-14), 7.21–7.16 (m, 2H, H-22, H-26), 7.10 (t, J = 8.0 Hz, 1H, H-25), 6.85 (s, 1H, H-20), 6.84–6.77 (m, 2H, H-1, H-24), 3.84 (s, 3H, OCH3). 13C NMR (125 MHz, DMSO-d6): 180.82 (Cq), 159.03 (Cq), 157.96 (Cq), 146.16 (Cq), 144.09 (CH), 135.90 (Cq), 135.12 (Cq), 130.29 (CH), 129.89 (CH), 129.34 (CH), 127.94 (CH), 126.64 (CH), 126.11 (Cq), 125.79 (CH), 123.32 (Cq), 119.75 (CH), 118.16 (CH), 114.98 (CH), 99.43 (CH), 56.33 (OCH3). HPLC purity: 98%. LRMS Exact Mass calcd for C22H17ClN4O2S: 436.076; m/z [M]+ found: 437 (100%); 438 (32%); 439 (42%).
3.2.22. (E)-N-(6-chloro-2-methoxyacridin-9-yl)-2-(4-(dimethylamino)benzylidene)hydrazine-1-carbothioamide (DL-09)
Rust orange solid; yield: 89%. MP: 149–150 °C. Rf 0.52 (n-hexane/ethyl acetate, 7:3). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.00 (s, 1H, NH), 8.93 (s, 1H, NH), 8.30 (d, J = 2.0 Hz, 1H, H-11), 8.20 (d, J = 9.5 Hz, 1H, H-4), 7.69–7.63 (m, 2H, H-3, H-13), 7.61 (d, J = 9.1 Hz, 1H, H-14), 7.59 (d, J = 8.7 Hz, 2H, H-22, H-26), 6.79 (d, J = 2.8 Hz, 1H, H-1), 6.73 (s, 1H, H-20), 6.62 (d, J = 8.5 Hz, 2H, H-23, H-25), 3.82 (s, 3H, OCH3), 2.92 (s, 6H, N(CH3)2). 13C NMR (125 MHz, DMSO-d6): δ ppm 180.30 (Cq), 158.76 (Cq), 151.98 (Cq), 147.54 (Cq), 147.45 (Cq), 144.24 (CH), 140.25 (Cq), 134.98 (Cq), 131.62 (CH), 130.04 (CH), 128.91 (CH), 127.93 (CH), 126.99 (CH), 126.01 (Cq), 125.79 (CH), 123.32 (Cq), 112.10 (CH), 99.40 (CH), 56.20 (OCH3), 40.44 (N(CH3)2). HPLC purity: 98%. LRMS Exact Mass calcd for C24H22ClN5OS: 463.123; m/z [M]+ found: 464 (100%); 465 (32%); 466 (44%).
3.2.23. (E)-2-(4-bromobenzylidene)-N-(6-chloro-2-methoxyacridin-9-yl)hydrazine-1-carbothioamide (DL-10)
Orange solid; yield: 75%. MP: 162–163 °C. Rf 0.65 (n-hexane/ethyl acetate, 7:3). 1H NMR (500 MHz, DMSO-d6): δ ppm 9.22 (s, 1H, NH), 9.16 (s, 1H, NH), 8.35 (d, J = 2.0 Hz, 1H, H-11), 8.24 (d, J = 9.5 Hz, 1H, H-4), 7.79 (d, J = 8.7 Hz, 2H, H-22, H-26), 7.67 (td, J = 8.0, 4.4 Hz, 2H, H-3, H-13), 7.61 (d, J = 9.2 Hz, 1H, H-14), 7.51 (d, J = 8.6 Hz, 2H, H-23, H-25), 6.88 (s, 1H, H-20), 6.77 (d, J = 2.8 Hz, 1H, H-1), 3.83 (s, 3H, OCH3). 13C NMR (125 MHz, DMSO-d6): δ ppm 180.94 (Cq), 158.92 (Cq), 147.25 (Cq), 142.44 (CH), 139.96 (Cq), 135.22 (Cq), 133.28 (Cq), 131.88 (CH), 131.35 (CH), 130.53 (CH), 129.15 (CH), 127.66 (CH), 127.28 (CH), 125.86 (Cq), 125.59 (CH), 124.28 (Cq), 123.11 (Cq), 99.21 (CH), 56.26 (OCH3). HPLC purity: 99%. LRMS Exact Mass calcd for C22H16BrClN4OS: 497.992; m/z [M]+ found: 499 (100%); 501 (100%).