反応 #1620

反応方程式

potassium carbonate

diethyl dibromomalonate

(R)-2-(3,4-dihydroxyphenyl)propylcarbamic acid, t-butyl ester

→

(R)-5-[N-(t-Butyloxycarbonyl)-2-aminopropyl]-1,3-benzodioxole-2,2-dicarboxylic acid, diethyl ester

溶媒

acetone

acetone

反応条件

後処理

1. 1
   温度After cooling to ambient temperature
2. 2
   workup.STIRRINGthe reaction was stirred at ambient temperature for 18 hours
3. 3
   ろ過The suspension was filtered
4. 4
   洗浄the residue was washed with ethyl acetate
5. 5
   その他evaporated
6. 6
   その他the residue was partitioned between ethyl acetate (200 ml) and dilute hydrochloric acid (100 ml, pH5)
7. 7
   その他The organic layer was separated
8. 8
   洗浄washed with water (2×100 ml) and brine (100 ml)
9. 9
   乾燥dried (MgSO4)
10. 10
    その他evaporated
11. 11
    その他The residue was purified by column chromatography on silica gel eluting with 25% ethyl acetate in n-hexane giving the title compound as an oil

実験手順

A solution of (R)-2-(3,4-dihydroxyphenyl)propylcarbamic acid, t-butyl ester. (1.07 g, 4 mMol) in acetone (25 ml) containing potassium carbonate (3 equiv, 1.66 g, 12 mMol) was stirred at 60° C. under an argon atmosphere for 1 hour. After cooling to ambient temperature, a solution of diethyl dibromomalonate (1.27 g, 4 mMol) in acetone (7 ml) was added and the reaction was stirred at ambient temperature for 18 hours. The suspension was filtered and the residue was washed with ethyl acetate. The filtrates were combined, evaporated and the residue was partitioned between ethyl acetate (200 ml) and dilute hydrochloric acid (100 ml, pH5). The organic layer was separated, washed with water (2×100 ml) and brine (100 ml), dried (MgSO4) and evaporated. The residue was purified by column chromatography on silica gel eluting with 25% ethyl acetate in n-hexane giving the title compound as an oil;

出典