Hydrochloric Acid → methyl ((1S,2R,4R,6S)-4-(3-aminopyridin-4-yl)-2-((tert-butoxycarbonyl)amino)-6-methylcyclohexyl)(methyl)carbamate

関与物質

反応手順

To a solution of (+/−)-tert-butyl ((1R,2S,3S,5R)-5-(3-((tert-butoxycarbonyl)amino)pyridin-4-yl)-3-methyl-2-(methylamino)cyclohexyl)carbamate (1.0 equiv.) in DCM (0.05 M) at 0° C. was added DIEA (3.0 equiv.) and then methyl chloroformate (1.5 equiv.). The homogeneous solution was left standing at 0° C. at for 4 hrs. The reaction was quenched partitioned between NaHCO3 solution and EtOAc. The organic layer was washed with Brine, dried over Na2SO4, concentrated and purified by ISCO chromatography. The product was treated with 4 M HCl in dioxane (30.0 equiv.) at rt for 1 hour. The volatiles were removed in vacuo and the solid was pumped on for 5 minutes on the high vac. To the residue was added CH2Cl2 (0.15 M), DIEA (5.0 equiv.) and tert-butyl 2,5-dioxopyrrolidin-1-yl carbonate (1.6 equiv.). The solution was left stirring at rt for 1 hr. The volatiles were removed in vacuo and the residue was partitioned between EtOAc and H2O. The organic layer was washed with Na2CO3(sat.), NaCl(sat.), dried over MgSO4, filtered, concentrated and purified by ISCO SiO2 chromatography to yield (+/−)-methyl ((1S,2R,4R,6S)-4-(3-aminopyridin-4-yl)-2-((tert-butoxycarbonyl)amino)-6-methylcyclohexyl)(methyl)carbamate in 20% yield. LC/MS (m/z)=393.2 (MH+), Rt=0.60 min.

情報源と証拠