[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[C:7](N)[N:6]=[CH:5]2.C(O[N+]([O-])=O)(C)(C)C.C([O-])(O)=O.[Na+].[Cl:26]CCCl>>[Cl:26][C:7]1[N:6]=[CH:5][C:4]2[C:9](=[CH:10][CH:11]=[C:2]([Cl:1])[CH:3]=2)[N:8]=1To a suspension of 6-chloro-quinazolin-2-ylamine (110) (2.8 g, 15.8 mmol) and SbCl3 (7.2 g, 32 mmol) in 1,2-dichloroethane (100 mL) was added tert-butylnitrate (6.2 ml, 52 mmol) and heated at 60° C. for 3 h under nitrogen atmosphere. To the mixture was added aqueous saturated NaHCO3 and the mixture was filtered off and filtrate was extracted with CHCl3. The organic layer was washed with brine, dried over Na2SO4, and evaporated. The residue was purified by silica gel column chromatography, using CHCl3/EtOAc (9:1, v/v) as eluent to give 2,6-dichloro-quinazoline (111) (0.65 g, 3.12 mmol, 20% yield).
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