反应详情

To a mechanically stirred suspension of 90 g of copper powder in 450 mL of dimethylformamide was added 90 g of methyl 4-iodo-2-methoxybenzoate (which was prepared as in Example 1). The resulting mixture was heated at reflux for 6 days and then cooled to room temperature and diluted into 1500 mL of chloroform. The mixture was filtered and the copper was washed with 2×150 mL of chloroform. The residual copper was suspended in 2 liters of water and extracted with 6×150 mL of chloroform. All the organic fractions were combined, dried and concentrated to approximately 250 mL. The concentrate was cooled to 0° C. and the precipitate filtered to give 33 g of 3,3'-dimethoxy-4,4'-bis(methoxycarbonyl)biphenyl as a pale yellow powder. Deprotection of the dimethoxy compound was accomplished with boron trichloride according to step 5 of Example 1 to yield 3,3'-dihydroxy-4,4'-bis(methoxycarbonyl)biphenyl. The structure was confirmed by NMR.

1. temperatureThe resulting mixture was heated
2. temperatureat reflux for 6 days
3. filtrationThe mixture was filtered
4. washthe copper was washed with 2×150 mL of chloroform
5. extractionextracted with 6×150 mL of chloroform
6. customdried
7. concentrationconcentrated to approximately 250 mL
8. temperatureThe concentrate was cooled to 0° C.
9. filtrationthe precipitate filtered