4.2. Synthesis of Methylamino Compound (±)-18
To a solution of 6-chloropurinyl nucleoside analogue (±)-17 (150 mg) in EtOH (10 mL), MeNH2 (4 eq.) was added. After heating under reflux for 20 h, the reaction mixture was concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel (eluent: n-hexane-EtOAc 1:1).
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Ethyl (S*)-4-((5-amino-6-chloropyrimidin-4-yl)amino)cyclopent-1-ene-1-carboxylate, (±)-16. |
Brownish white solid, m.p. 121–123 °C, 40%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.30 (t, 3H, CH3, J = 7.14 Hz), 2.43–2.59 (m, 2H, CH2), 3.00–3.16 (m, 2H, CH2), 3.44 (brs, 2H, NH2), 4.17–4.25 (m, 2H, OCH2), 4.79–4.86 (m, 1H, H-4), 5.08 (d, 1H, N-H, J = 5.76 Hz), 6.76-6.78 (m, 1H, H-2), 8.08 (s, 1H, Ar-H); 13C-NMR (DMSO, 100 MHz): δ (ppm) = 15.0, 39.3, 41.2, 51.3, 60.7, 124.6, 135.1, 137.7, 142.6, 146.4, 152.0, 164.9; MS (ES, pos) m/z = 283 (M + 1).
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Ethyl (S*)-4-(6-chloro-9H-purin-9-yl)cyclopent-1-ene-1-carboxylate, (±)-17. |
Yellowish white solid, m.p. 83–85 °C, 81%; 1H-NMR (DMSO, 400 MHz): δ = 1.20 (t, 3H, CH3, J = 7.08 Hz), 2.93–3.05 (m, 2H, CH2), 3.06–3.20 (m, 2H, CH2), 4.09–4.17 (m, 2H, OCH2), 5.38–5.47 (m, 1H, H-4), 6.70–6.81 (m, 1H, H-2), 8.69 (s, 1H, Ar-H), 8.74 (s, 1H, Ar-H); 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 14.6, 39.2, 40.9, 54.2, 61.2, 132.2, 135.5, 140.1, 143.5, 151.6, 151.8, 152.3, 164.2; MS (ES, pos) m/z = 293 (M + 1).
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Ethyl (S*)-4-(6-(methylamino)-9H-purin-9-yl)cyclopent-1-ene-1-carboxylate, (±)-18. |
Yellow oil, 68%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.32 (t, 3H, CH3, J = 7.12 Hz), 2.86–3.03 (m, 2H, CH2), 3.10–3.29 (m, 5H, NCH3 and CH2), 4.20–4.31 (m, 2H, OCH2), 5.41–5.50 (m, 1H, H-4), 6.16 (brs, 1H, N-H), 6.86–6.89 (m, 1H, H-2), 7.75 (s, 1H, Ar-H), 8.41 (s, 1H, Ar-H); 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 14.6, 39.3, 41.1, 50.6, 58.9, 61.1, 120.4, 135.5, 136.1, 137.7, 140.5, 153.4, 155.9, 164.5; MS (ES, pos) m/z = 288 (M + 1).
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Ethyl (S*)-4-(6-(cyclopropylamino)-9H-purin-9-yl)cyclopent-1-ene-1-carboxylate, (±)-19. |
Yellow oil, 53%; 1H-NMR (CDCl3, 500 MHz): δ (ppm) = 0.64–0.69 (m, 2H, CH2), 0.90–0.97 (m, 2H, CH2), 1.32 (t, 3H, CH3, J = 7.13 Hz), 2.86–3.08 (m, 3H, CH2), 3.18–3.32 (m, 2H, CH2, CH), 4.21–4.28 (m, 2H, OCH2), 5.35–5.43 (m, 1H, H-4), 6.03 (brs, 1H, N-H), 6.86-6.91 (m, 1H, H-2), 7.75 (s, 1H, Ar-H), 8.48 (s, 1H, Ar-H); 13C-NMR (CDCl3, 126 MHz): δ (ppm) = 7.4, 14.3, 23.7, 38.9, 40.8, 52.9, 60.7, 119.9, 135.1, 137.6, 140.2, 153.2, 155.8, 164.1; MS (ES, pos) m/z = 314 (M + 1).
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Ethyl (S*)-4-(6-azido-9H-purin-9-yl)cyclopent-1-ene-1-carboxylate, (±)-20. |
White solid, m.p. 145–147 °C, 68%; 1H-NMR (DMSO, 400 MHz): δ (ppm) = 1.22 (t, 3H, CH3, J = 7.08 Hz), 2.97–3.09 (m, 2H, CH2), 3.22–3.28 (m, 2H, CH2), 4.12–4.23 (m, 2H, OCH2), 5.53–5.64 (m, 1H, H-4), 6.86–6.89 (m, 1H, H-2), 8.66 (s, 1H, Ar-H), 10.07 (s, 1H, Ar-H); 13C-NMR (DMSO, 100 MHz): δ (ppm) = 15.0, 34.9, 39.2, 55.1, 61.0, 121.2, 134.5, 136.3, 141.8, 142.8, 143.8, 146.3, 164.5; MS (ES, pos) m/z = 300 (M + 1).
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Ethyl (1R*,6S*)-6-((5-amino-6-chloropyrimidin-4-yl)amino)cyclohex-3-ene-1-carboxylate, (±)-23. |
White solid, m.p. 120–121 °C, 42%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.28 (t, 3H, CH3, J = 7.12 Hz), 2.26–2.38 (m, 1H, CH2), 2.42–2.56 (m, 2H, CH2), 2.62–2.73 (m, 1H, CH2), 2.95–3.03 (m, 1H, H-1), 3.39 (brs, 2H, NH2), 4.11–4.24 (m, 2H, OCH2), 4.74–4.85 (m, 1H, H-6), 5.66–5.87 (m, 3H, H-3, H-4, N-H), 8.08 (s, 1H, Ar-H); 13C-NMR (DMSO, 100 MHz): δ (ppm) = 14.8, 25.5, 30.4, 41.4, 47.1, 60.6, 124.6, 125.4, 125.9, 138.0, 146.1, 152.2, 173.4; MS (ES, pos) m/z = 297 (M + 1), 299 (M + 3).
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Ethyl (1R*,6S*)-6-(6-chloro-9H-purin-9-yl)cyclohex-3-ene-1-carboxylate, (±)-24. |
Yellow oil, 76%. 1H-NMR (DMSO, 400 MHz): δ (ppm) = 0.98 (t, 3H, CH3, J = 7.12 Hz), 2.31–2.52 (m, 2H, CH2), 2.74–2.84 (m, 2H, CH2), 3.28–3.33 (m, 1H, H-1), 3.83–3.90 (m, 2H, OCH2), 5.25–5.32 (m, 1H, H-6), 5.85–5.89 (m, 2H, H-3, H-4), 8.56 (s, 1H, Ar-H), 8.78 (s, 1H, Ar-H). 13C-NMR (DMSO, 100 MHz): δ (ppm) = 14.5, 25.4, 29.3, 42.0, 51.2, 61.2, 125.3, 126.4, 131.2, 146.6, 149.9, 152.2, 153.0, 172.4; MS (ES, pos) m/z = 307 (M + 1).
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Ethyl (1R*,6S*)-6-(6-azido-9H-purin-9-yl)cyclohex-3-ene-1-carboxylate, (±)-25. |
White solid, m.p. 130–132 °C, 51%; 1H-NMR (DMSO, 400 MHz): δ (ppm) = 1.03 (t, 3H, CH3, J = 7.10 Hz), 2.34–2.65 (m, 2H, CH2), 2.78–3.00 (m, 2H, CH2), 3.31–3.43 (m, 1H, H-1), 3.82–4.00 (m, 2H, OCH2), 5.40-5.48 (m, 1H, H-6), 8.54 (s, 1H, Ar-H), 10.13 (s, 1H, Ar-H); 13C-NMR (DMSO, 100 MHz): δ (ppm) = 14.6, 25.4, 29.7, 42.3, 51.5, 61.3, 125.3, 126.4, 129.4, 130.4, 135.3, 142.8, 147.9, 170.5; MS (ES, pos) m/z = 314 (M + 1).
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Ethyl (1R*,6S*)-6-(6-(cyclopropylamino)-9H-purin-9-yl)cyclohex-3-ene-1-carboxylate, (±)-26. |
White solid, m.p. 128–129 °C, 62%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 0.61–0.65 (m, 2H, CH2), 0.88–0.93 (m, 2H, CH2), 1.20 (t, 3H, CH3), 2.48–2.55 (m, 2H, CH2), 2.70–2.74 (m, 2H, CH2), 2.99–3.04 (m, 1H, H-1), 3.14–3.20 (m, 1H, CH), 3.97–4.08 (m, 2H, OCH2), 5.30–5.38 (m, 1H, H-6), 5.91–5.98 (m, 2H, H-3, H-4), 6.04 (brs, 1H, N-H), 7.98 (s, 1H, Ar-H), 8.44 (s, 1H, Ar-H); 13C-NMR (CDCl3, 126 MHz): δ (ppm) = 7.4, 13.9, 23.7, 25.2, 29.8, 42.0, 49.2, 61.0, 119.3, 124.8, 125.9, 139.0, 148.6, 153.0, 155.7, 172.1; MS (ES, pos) m/z = 328 (M + 1).
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Ethyl (1S*,6S*)-6-((5-amino-6-chloropyrimidin-4-yl)amino)cyclohex-3-ene-1-carboxylate, (±)-29. |
White solid, m.p. 120–121 °C, 42%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.19 (t, 3H, CH3, J = 7.12 Hz), 2.03–2.12 (m, 1H, CH2), 2.34–2.43 (m, 1H, CH2), 2.56–2.75 (m, 2H, CH2), 2.83–2.92 (m, 1H, H-1), 3.47 (brs, 2H, NH2), 4.06–4.16 (m, 2H, OCH2), 4.62–4.69 (m, 1H, H-6), 5.13 (d, 1H, N-H, J = 8.12 Hz), 5.66–5.78 (m, 2H, H-3, H-4), 8.09 (s, 1H, Ar-H); 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 14.5, 27.5, 31.9, 45.2, 48.5, 61.3, 122.1, 124.2, 125.1, 143.7, 150.1, 154.8, 174.1; MS (ES, pos) m/z = 297 (M + 1).
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Ethyl (1S*,6S*)-6-(6-chloro-9H-purin-9-yl)cyclohex-3-ene-1-carboxylate, (±)-30. |
Colorless oil, 58%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 0.96 (t, 3H, CH3, J = 7.12 Hz), 2.53–2.68 (m, 3H, CH2), 3.01–3.07 (m, 1H, CH2), 3.56–3.66 (m, 1H, H-1), 3.86–3.96 (m, 2H, OCH2), 4.94–5.03 (m, 1H, H-6), 5.78−5.89 (m, 2H, H-3, H-4), 8.17 (s, 1H, Ar-H), 8.76 (s, 1H, Ar-H); 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 14.2, 29.0, 30.7, 44.1, 54.5, 61.4, 124.4, 125.6, 132.2, 145.3, 151.5, 151.9, 152.1, 173.0; MS (ES, pos) m/z = 307 (M + 1).
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Ethyl (1S*,6S*)-6-(6-azido-9H-purin-9-yl)cyclohex-3-ene-1-carboxylate, (±)-31. |
White solid, m.p. 140–141 °C, 68%; 1H-NMR (DMSO, 400 MHz): δ (ppm) = 0.74 (t, 3H, CH3, J = 7.08 Hz), 2.46–2.57 (m, 3H, CH2), 2.86–3.00 (m, 1H, CH2), 3.60–3.66 (m, 1H, H-1), 3.69–3.76 (m, 2H, OCH2), 5.08–5.15 (m, 1H, H-6), 5.80–5.92 (m, 2H, H-3, H-4), 8.79 (s, Ar-H), 10.13 (s, 1H, Ar-H). 13C-NMR (DMSO, 100 MHz): δ (ppm) = 14.3, 29.3, 31.9, 44.7, 54.3, 61.1, 125.1, 125.9, 136.5, 139.3, 142.9, 144.6, 146.3, 173.1. MS (ES, pos) m/z = 314 (M + 1).
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Ethyl (1R*,2S*)-2-((5-amino-6-chloropyrimidin-4-yl)amino)cyclohex-3-ene-1-carboxylate, (±)-34. |
Brown oil, 55%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.20 (t, 3H, CH3, J = 7.14 Hz), 1.99–2.19 (m, 4H, CH2), 2.99–3.05 (m, 1H, H-1), 4.00–4.17 (m, 2H, OCH2), 5.23–5.26 (m, 1H, H-2), 5.59 (d, 1H, N-H, J = 9.04 Hz), 5.70–5.78 (m, 1H, H-4), 5.87–5.92 (m, 1H, H-3), 8.06 (s, 1H, Ar-H), 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 14.5, 22.7, 23.6, 43.4, 46.9, 61.1, 122.4, 127.5, 130.0, 143.4, 149.7, 154.6, 174.2; MS (ES, pos) m/z = 297 (M + 1).
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Ethyl (1R*,2S*)-2-(6-chloro-9H-purin-9-yl)cyclohex-3-ene-1-carboxylate, (±)-35. |
Brown solid, m.p. 119–121 °C, 68%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.03 (t, 3H, CH3, J = 7.14 Hz), 2.00–2.08 (m, 2H, CH2), 2.27–2.33 (m, 1H, CH2), 2.41–2.46 (m, 1H, CH2), 3.12–3.20 (m, 1H, H-1), 3.72–3.87 (m, 2H, OCH2), 5.67–5.70 (m, 1H, H-2), 5.83–5.90 (m, 1H, H-4), 6.28–6.33 (m, 1H, H-3), 8.23 (s, 1H, Ar-H), 8.73 (s, 1H, Ar-H); 13C-NMR (DMSO, 100 MHz): δ (ppm) = 14.3, 20.3, 24.4, 44.1, 50.1, 61.0, 123.1, 134.8, 147.5, 147.8, 149.9, 152.3, 152.9, 172.4; MS (ES, pos) m/z = 307 (M + 1), 309 (M + 3).
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Ethyl (1R*,2S*)-2-((5-amino-6-chloropyrimidin-4-yl)amino)cyclopent-3-ene-1-carboxylate, (±)-38. |
Brownish white solid, m.p. 104–106 °C, 34%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 1.04 (t, 3H, CH3, J = 7.12 Hz), 2.56–2.67 (m, 1H, CH2), 2.83–2.90 (m, 1H, CH2), 3.44–3.54 (m, 1H, H-1), 3.57 (brs, 2H, NH2), 3.85–4.02 (m, 2H, OCH2), 5.34 (d, 1H, N-H, J = 8.76 Hz), 5.69–5.76 (m, 2H, H-2, H-4), 5.98–6.01 (m, 1H, H-3), 8.06 (s, 1H, Ar-H); 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 14.2, 35.4, 46.4, 58.2, 61.1, 122.6, 130.2, 134.0, 143.0, 149.3, 154.1, 174.0; MS (ES, pos) m/z = 283 (M + 1), 285 (M + 3).
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Ethyl (1R*,2S*)-2-(6-chloro-9H-purin-9-yl)cyclopent-3-ene-1-carboxylate, (±)-39. |
Yellowish white solid, m.p. 118–119 °C, 39%; 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 0.72 (t, 3H, CH3, J = 7.14 Hz), 2.76–2.85 (m, 1H, CH2), 3.14–3.23 (m, 1H, CH2), 3.49–3.56 (m, 1H, H-1), 3.65–3.77 (m, 2H, OCH2), 5.86–5.89 (m, 1H, H-2), 5.15–5.17 (m, 1H, H-4), 6.44–6.47 (m, 1H, H-3), 7.99–8.01 (m, 1H, Ar-H), 8.78–8.81 (m, 1H, Ar-H); 13C-NMR (CDCl3, 100 MHz): δ (ppm) = 13.8, 34.9, 47.2, 60.9, 61.4, 126.8, 134.7, 138.7, 150.0, 152.2, 152.3, 154.2, 170.9; MS (ES, pos) m/z = 293 (M + 1), 295 (M + 3).
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((1R*,6S*)-6-((5-Amino-6-chloropyrimidin-4-yl)amino)cyclohex-3-en-1-yl)methanol, (±)-42. |
White solid, m.p. 186–188 °C, 60%; 1H-NMR (DMSO, 400 MHz): δ (ppm) = 1.96–2.12 (m, 4H, CH2), 2.21–2.30 (m, 1H, H-1), 3.24–3.32 (m, 1H, OCH2), 3.40-3.49 (m, 1H, OCH2), 4.43–4.48 (m, 2H, H-6 and O-H), 5.16 (brs, 2H, N-H), 5.59–5.70 (m, 2H, H-3, H-4), 6.24 (d, 1H, N-H, J = 7.56 Hz), 7.68 (s, 1H, Ar-H); 13C-NMR (DMSO, 100 MHz): δ (ppm) = 25.9, 30.1, 39.8, 47.2, 61.4, 124.5, 125.6, 126.6, 138.0, 146.4, 152.6; MS (ES, pos) m/z = 255 (M + 1), 257 (M + 3).
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((1R*,6S*)-6-(6-Chloro-9H-purin-9-yl)cyclohex-3-en-1-yl)methanol, (±)-43. |
White solid, m.p. 109–111 °C, 76%, 1H-NMR (CDCl3, 500 MHz): δ (ppm) = 1.36–1.47 (m, 1H, CH2), 2.05–2.15 (m, 1H, CH2), 2.34–2.44 (m, 1H, H-1), 2.50–2.59 (m, 1H, CH2), 2.73–2.81 (m, 1H, OCH2), 2.93–3.03 (m, 1H, CH2), 3.44–3.53 (m, 1H, OCH2), 4.65 (brs, 1H, OH), 5.31–5.37 (m, 1H, H-6), 5.98–6.06 (m, 2H, H-3, H-4), 8.33 (s, 1H, Ar-H), 8.76 (s, 1H, Ar-H); 13C-NMR (CDCl3, 126 MHz): 22.6, 31.0, 39.7, 48.6, 62.1, 124.7, 127.8, 131.1, 144.6, 151.6, 151.7, 152.5, MS (ES, pos) m/z = 265 (M + 1), 267 (M + 3).
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((1S*,6S*)-6-((5-Amino-6-chloropyrimidin-4-yl)amino)cyclohex-3-en-1-yl)methanol, (±)-46. |
White solid, m.p. 164–167 °C, 64%; 1H-NMR (DMSO, 400 MHz): δ (ppm) = 1.70–1.84 (m, 1H, CH2), 1.89–2.05 (m, 2H, CH2), 2.14–2.25 (m, 1H, CH2), 2.26–2.36 (m, 1H, H-1), 3.26–3.43 (m, 2H, OCH2), 4.05–4.15 (m, 1H, H-6), 4.36 (t, 1H, O-H, J = 5.32 Hz), 4.99 (brs, 2H, N-H), 5.51-5.67 (m, 2H, H-3, H-4), 6.50 (d, 1H, N-H, J = 7.96 Hz), 7.64 (s, 1H, Ar-H), 13C-NMR (DMSO, 100 MHz): δ (ppm) = 28.7, 32.3, 41.3, 48.3, 62.9, 124.2, 125.5, 127.3, 137.7, 146.4, 152.7, MS (ES, pos) m/z = 255 (M + 1), 257 (M + 3).
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((1S*,6S*)-6-(6-Chloro-9H-purin-9-yl)cyclohex-3-en-1-yl)methanol, (±)-47. |
White solid, m.p. 160–162 °C, 70%; 1H-NMR (DMSO, 500 MHz): δ (ppm) = 2.13–2.29 (m, 2H, CH2), 2.42–2.49 (m, 1H, CH2), 2.53–2.62 (m, 1H, H-1), 2.83–2.95 (m, 1H, CH2), 2.98–3.05 (m, 1H, OCH2), 3.11–3.17 (m, 1H, OCH2), 4.69–4.78 (m, 1H, H-6), 5.68–5.85 (m, 2H, H-3, H-4), 8.73–8.78 (m, 2H, Ar-H), 13C-NMR (DMSO, 126 MHz): 28.5, 31.3, 39.0, 54.1, 61.7, 124.6, 127.2, 131.6, 147.6, 149.4, 151.7, 152.4; MS (ES, pos) m/z = 265 (M + 1), 267 (M + 3).