反应详情

To a slurry of LiAlH4 (1.61 g, 42.54 mmol) in dry THF (75 mL) cooled to −78° C., a solution of dimethyl 4,5-dichlorobenzene-1,2-dicarboxylic acid (5.0 g, 21.27 mmol) in dry THF (25 mL) was added dropwise over a period of 1 h. After slow warming of the system to RT over a period of 2 h the mixture was heated at reflux overnight. The heterogeneous mixture was then cooled to 0° C. and sodium hydroxide solution (15%, 100 mL) cooled to 0° C. was very slowly added. This was followed by addition of ice-cold water (100 mL), and the reaction mixture was diluted with diethyl ether (200 mL) and the organic layer was separated, dried over MgSO4. Removal of solvents gave a white solid which was passed through a pad of silica gel to afford pure product in 88% yield (3.85 g). 1H NMR (500 MHz, CDCl3): δ 7.60 (s, 2H), 4.65 (s, 4H), 4.50 (bs, 2H).

1. temperaturewas heated
2. temperatureat reflux overnight
3. temperatureThe heterogeneous mixture was then cooled to 0° C.
4. additionwas very slowly added
5. customthe organic layer was separated
6. dry with materialdried over MgSO4
7. customRemoval of solvents
8. customgave a white solid which
9. customto afford pure product in 88% yield (3.85 g)