反应详情

A hexane solution (17 ml) of n-butyllithium was dropwise added to a tetrahydrofuran (190 ml) solution of 4-benzyloxy-2-bromo-5-methoxytoluene (7.83 g) at −78° C. over a period of 20 minutes, followed by stirring at the same temperature for 1 hour. A tetrahydrofuran (10 ml) solution of dimethylformamide (3.73 g) was dropwise added thereto at −78° C., followed by stirring at the same temperature for 1 hour. The temperature was gradually raised to room temperature, and stirring was further carried out for one night. The reaction solution was poured into an aqueous ammonium chloride solution (200 ml), and extraction with ethyl acetate (150 ml) was carried out twice. The ethyl acetate phase was washed with an aqueous sodium chloride solution (100 ml) twice and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane-ethyl acetate) to obtain 3.14 g (yield 48%) of 5-benzyloxy-4-methoxy-2-methylbenzaldehyde (m.p. 107-109° C.), and its structure was confirmed by nuclear magnetic resonance spectrum.

1. customat −78° C.
2. stirringby stirring at the same temperature for 1 hour
3. stirringstirring
4. waitwas further carried out for one night
5. washThe ethyl acetate phase was washed with an aqueous sodium chloride solution (100 ml) twice
6. dry with materialdried over magnesium sulfate
7. distillationthe solvent was distilled off under reduced pressure
8. customThe residue was purified by silica gel column chromatography (hexane-ethyl acetate)