反应详情

1-(3,5-Diamino-6-chloropyrazinoyl)-2-methyl-pseudothiourea hydroiodide (II, 494 mg, 1.27 mmol) was dissolved in a mixture of anhydrous DMF (10 mL), and triethylamine (3 mL) followed by treatment with N-(benzyloxycarbonyloxy) succinimide (470 mg, 1.7 mmol) dissolved in DMF (3 mL). The reaction mixture was stirred overnight at room temperature. After this time, the reaction mixture was concentrated under reduced pressure and the residue suspended in ethyl acetate (30 mL). Silica gel (25 g) was added to the solution and the solvent was evaporated to leave the silica gel impregnated with the crude product that was purified by flash chromatography on a FlashElute™ system from Elution Solution (P.O. Box 5147, Charlottesville, Va. 22905) using a 90 g silica gel cartridge (eluent: hexanes, ethyl acetate=1:2). The purified N-Cbz-1-(3,5-diamino-6-chloropyrazinoyl)-2-methyl-pseudothiourea (III) was obtained as a pale yellow solid: 416 mg (83% yield); 1H NMR (360 MHz, DMSO-d6) δ 2.33 (s, 3H), 2.61 (s, 3H), 4.99 (s, 2H), 7.39 (m, 10H), 13.7 (s, 1H); API MS m/z=395 [C15H15ClN6O3S+H]+; LC/MS (Method A) >99%, tr=10.1 min.

1. concentrationAfter this time, the reaction mixture was concentrated under reduced pressure
2. additionSilica gel (25 g) was added to the solution
3. customthe solvent was evaporated
4. customto leave the silica gel
5. customwas purified by flash chromatography on a FlashElute™ system from Elution Solution (P.O. Box 5147, Charlottesville, Va. 22905)