反应详情

5-(4-Acetoxyphenyl)-3-benzyl-2-bis(methanesulfonyl)aminopyrazine (c-39) (239 mg, 503 μmol) was suspended in methanol (5 mL) and to this was added 10% (w/v) aqueous solution of sodium hydroxide (1.2 mL) while stirring at room temperature and then stirred at 65° C. for 30 min. After cooling to room temperature, to this was added 2 M hydrochloric acid to stop the reaction and extracted twice with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. After removing anhydrous sodium sulfate by filtration, the filtrate was concentrated under reduced pressure with a rotary evaporator. The residue was purified by column chromatography (23 g, n-hexane/ethyl acetate=1/1) to give 3-benzyl-5-(4-hydroxyphenyl)2-(methanesulfonylamino)pyrazine (coelenteramesylamide) (c-34) as a pale yellow solid (166 mg, 92.6%). Rf=0.30 (n-hexane/ethyl acetate=1/1). Mp. 208-209° C. (dec.). UV (MeOH) λmax (log ε) 335 (4.12), 290 (4.25), 276 (4.27). UV (pH 7.4 PB) λmax (log ε) 349 (4.14), 281 (4.38). 1H NMR (400 MHz, DMSO-d6) δ 3.36 (s, 3H), 4.25 (s, 2H), 6.82-6.87 (AA′BB′, 2H), 7.15-7.23 (m, 1H), 7.29 (d, J=5.0 Hz, 4H), 7.83-7.88 (AA′BB′, 2H), 8.73 (s, 1H), 9.80 (s, 1H), 10.41 (s, 1H). 13C NMR (75.5 MHz, DMSO-d6) δ 38.2, 42.7, 115.8 (2C), 126.4, 126.6, 127.7 (2C), 128.4 (2C), 129.0 (2C), 135.9, 138.1, 144.3, 146.0, 146.4, 158.8. IR (KBr, cm−1) 521, 538, 588, 606, 700, 750, 827, 841, 889, 916, 939, 970, 1118, 1138, 1153, 1175, 1213, 1273, 1314, 1400, 1456, 1495, 1609, 3206. HRMS (FAB+) m/z 356.1060 (M+H, C18H18N3O3S requires 356.1069).

1. stirringstirred at 65° C. for 30 min
2. temperatureAfter cooling to room temperature
3. customthe reaction
4. extractionextracted twice with ethyl acetate
5. washThe organic layer was washed with saturated brine
6. dry with materialdried over anhydrous sodium sulfate
7. customAfter removing anhydrous sodium sulfate
8. filtrationby filtration
9. concentrationthe filtrate was concentrated under reduced pressure with a rotary evaporator
10. customThe residue was purified by column chromatography (23 g, n-hexane/ethyl acetate=1/1)