反应详情

Preparation of methyl-(4-cyano-4-ethoxycarbonylbutyl)benzoate ##STR21## To a 250 mL flame dried round bottom flask were charged 10.0 g (51.5 mmol) of methyl 4-(-hydroxypropyl)benzoate and 5.48 mL (51.5 mmol) of ethyl cyanoacetate dissolved in 40 mL of anhydrous tetrahydrofuran (THF). To this solution was then added dropwise to a solution of 20.2 g (77 mmol) of triphenylphosphine and 12.1 mL (77 mmol) of diethyl azodicarboxylate dissolved in 60 mL of anhydrous THF. After the addition, the reaction was stirred at ambient temperature for 1.5 hours. The volatiles were removed in vacuo and the crude oil was dissolved in 300 mL of EtOAc, washed with brine, dried over Na2SO4, and removed in vacuo. This crude oil was then purified on silica gel using a Waters Prep LC 2000 eluting with a gradient of 1:1 MeCl2 /Hex to 100% MeCl2 to give 6.0 g (40%) of methyl 4-(4-cyano-4-ethoxycarbonylbutyl)benzoate as a pale yellow oil.

1. temperatureflame
2. customdried round bottom flask
3. additionAfter the addition
4. customThe volatiles were removed in vacuo
5. dissolutionthe crude oil was dissolved in 300 mL of EtOAc
6. washwashed with brine
7. dry with materialdried over Na2SO4
8. customremoved in vacuo
9. customThis crude oil was then purified on silica gel using a Waters Prep LC 2000 eluting with a gradient of 1:1 MeCl2 /Hex to 100% MeCl2