[CH3:1][C:2]1[C:6]2[CH:7]=[C:8]([N+:11]([O-])=O)[CH:9]=[CH:10][C:5]=2[O:4][N:3]=1.O.O.[Sn](Cl)Cl.Cl>CC(O)=O>[CH3:1][C:2]1[C:6]2[CH:7]=[C:8]([NH2:11])[CH:9]=[CH:10][C:5]=2[O:4][N:3]=1To a stirred solution of 3-methyl-5-nitrobenzo[d]isoxazole (Step 33.2) (1.8 g, 10.10 mmol) in AcOH (40 mL) was added a solution of tin(II) chloride dihydrate (6.84 g, 30.3 mmol) in HCl (15 mL, 494 mmol). The reaction mixture was stirred for 1 hr at 100° C., quenched with a saturated aq. NaHCO3 solution, diluted with water, and extracted with CH2Cl2. The combined organic layers were washed once with a saturated aq. NH4Cl solution, dried over Na2SO4 and evaporated. The crude material was purified by silica gel column chromatography (hexane/EtOAc 20-50) to afford the title product (458 mg, 3.09 mmol, 31% yield) as a pink solid. tR: 0.50 min (LC-MS 2); ESI-MS: 149 [M+H]+ (LC-MS 2); Rf=0.45 (hexane/EtOAc 1:1).
読み込み中…