反应详情

2-Amino-6-methoxybenzothiazole (3.0 g) was added to a solution (100 mL) of potassium hydroxide (21.9 g) in water, followed by refluxing under heating for 15 hours. The mixture was neutralized with 5N aqueous acetic acid solution, and the precipitated crystals were recovered through filtration. The procedure of Referential Example 22 was repeated, except that the thus-recovered 2-amino-5-methoxy-1-benzenethiol (185 mg) and 3-bromo-4-(1,3-oxazol-5-yl)benzaldehyde (300 mg), which had been produced in Referential Example 26, were used, to thereby yield 5-[2-bromo-4-(6-methoxy-1,3-benzothiazol-2-yl)phenyl]-1,3-oxazole (450 mg). Subsequently, The procedure of Referential Example 12 was repeated, except that 5-[2-bromo-4-(6-methoxy-1,3-benzothiazol-2-yl)phenyl]-1,3-oxazole (450 mg) was used, to thereby yield 5-[4-(6-methoxy-1,3-benzothiazol-2-yl)-2-(1,1,1-tributylstannyl)phenyl]-1,3-oxazole (15 mg). Thereafter, the procedure of Example 12 was repeated, except that 5-[4-(6-methoxy-1,3-benzothiazol-2-yl)-2-(1,1,1-tributylstannyl)phenyl]-1,3-oxazole (15 mg) was used, to thereby yield 5-[2-iodo-4-(6-methoxy-1,3-benzothiazol-2-yl)phenyl]-1,3-oxazole. Under a stream of argon, boron tribromide (200 μL, 1M dichloromethane solution) was added dropwise to a solution (30 mL) of 5-[2-iodo-4-(6-methoxy-1,3-benzothiazol-2-yl)phenyl]-1,3-oxazole (20 mg) in dichloromethane, and the mixture was stirred at room temperature for 23 hours. 1N Aqueous hydrochloric acid solution was added to the reaction mixture, followed by extraction with ethyl acetate. The solvent was evaporated, and the residue was purified through silica gel column chromatography (n-hexane:ethyl acetate=1:1), to thereby yield the title compound (10 mg).

1. temperatureby refluxing
2. temperatureunder heating for 15 hours
3. filtrationthe precipitated crystals were recovered through filtration
4. customhad been produced in Referential Example 26
5. extractionfollowed by extraction with ethyl acetate
6. customThe solvent was evaporated
7. customthe residue was purified through silica gel column chromatography (n-hexane:ethyl acetate=1:1)