反应详情

The benzaldehyde used in Example 6 was prepared as follows: (1) To a stirred solution of 2.91 g (16.14 mmol) of 3-methoxy-4-(1,1-dimethylethyl)phenol (see C. J. R. Adderley and F. R. Hewgill, J. Chem. Soc., (C), 1438, (1968) as an example of how to obtain this material) in 65 ml of methylene chloride and cooled in an ice-water bath was added 6.12 g (3.54 ml, 32.30 mmol) of titanium (IV) chloride followed by 3.06 g (2.41 ml, 26.64 mmol) of 1,1-dichlorodimethyl ether. The reaction mixture was stirred for 10 minutes and then poured into 16 ml of lN hydrochloric acid. The organic phase was separated, dried and evaporated. The residue was chromatographed on silica gel (146 g) using 1.5:98.5 (v/v) ether,hexane as eluent. There was obtained 2.92 g (14.01 mmol, 87%) of 2-hydroxy-4-methoxy-5-(1,1-dimethylethyl)benzaldehyde as a white solid after crystallization from pentane; mp 75°-78° C.

1. customwas prepared
2. temperaturecooled in an ice-water bath
3. customThe organic phase was separated
4. customdried
5. customevaporated
6. customThe residue was chromatographed on silica gel (146 g)