反应详情

To a stirred solution of 1-(2-amino-pyridin-4-ylmethyl)-1H-benzo[d][1,3]oxazine-2,4-dione (600 mg, see preparation 7b) in pyridine (7 ml) was added methanesulfonyl chloride (280 mg) and the reaction mixture was stirred at room temperature for 15 hours. The solvent was evaporated under reduced pressure and the residue was dissolved in EtOAc and washed with water and brine. The organic layer was dried (MgSO4) and evaporated under reduced pressure. The remaining solid yellow material was dissolved in a mixture of hot EtOAc (50 ml) and DMF (4 ml). On cooling a solid material formed, that was isolated by filtration and dried under vacuum, affording N-[4-(2,4-dioxo-4H-benzo[d][1,3]oxazin-1-ylmethyl)-pyridin-2-yl]-methanesulfonamide. Step 2: This anhydride intermediate was converted into the title compound by reaction with O-cyclopentylmethyl-hydroxylamine hydrochloride (see preparation 66), using general procedure 1A. 13C-NMR (DMSO-d6) δ 166.8, 152.9, 152.6, 148.3, 132.4, 127.9, 115.2, 114.8, 113.3, 111.4, 110.1, 79.4, 45.0, 41.5, 37.6, 28.9, 24.9.