反应详情

20.0 g (0.13 moles) of 2-bromopropionic acid were stirred with 14.1 g (0.13 moles) of benzyl alcohol in dry methylene chloride at 5°-10° C., before 0.16 g (1.3e-3 moles) of 4-dimethylaminopyridine (DMAP) were added. The temperature was raised to ~15° C. before a solution of dicyclohexylcarbodiimide (DCC) (26.7 g, 0.13 moles) in dry methylene chloride was added dropwise. The solution was added at a rate as to not increase the reaction temperature above 35° C. After the imide addition was complete, the reaction proceeded at 25° C. for several hours or until infrared spectroscopy analysis indicated the absence of a carboxylic acid stretch at 1730 cm-1. Upon completion, the reaction mixture was filtered under vacuum to remove the dicyclohexyl urea (DCU) byproduct and the filtrate was extracted once with water, once with 5% acetic acid solution (to remove DMAP) and again with water. The organic layer was dried over anhydrous magnesium sulfate before being filtered and concentrated under reduced pressure. Yield was 25 g (72%) of a mixture of Benzyl-2-bromopropionate and Benzyl-2-chloropropionate.

1. additionwere added
2. additionwas added dropwise
3. additionThe solution was added at a rate as to not
4. temperatureincrease the reaction temperature above 35° C
5. waitthe reaction proceeded at 25° C. for several hours
6. filtrationUpon completion, the reaction mixture was filtered under vacuum
7. customto remove the dicyclohexyl urea (DCU) byproduct
8. extractionthe filtrate was extracted once with water, once with 5% acetic acid solution (to remove DMAP) and again with water
9. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
10. filtrationbefore being filtered
11. concentrationconcentrated under reduced pressure