反応 #2446122

反応方程式

3-(8-hydroxyquinolin-5-yl)alanine

thionyl chloride

ethanol

→

3-(8-hydroxyquinolin-5-yl)alanine ethyl ester

収率 92.0%

溶媒

N2

反応条件

後処理

1. 1
   温度refluxed overnight
2. 2
   その他The solution was evaporated to dryness in vacuum
3. 3
   workup.DISSOLUTIONThe residue was dissolved in absolute ethanol
4. 4
   その他reevaporated to dryness
5. 5
   その他was further purified by FC(CH2Cl2:MeOH:AcOH 9:1.5:1.5)

実験手順

To a stirred slurry of DL-3-(8-hydroxyquinolin-5-yl)alanine (HLM8) (2.19 g, 7.04 mmol) in absolute ethanol (26 ml) at 0° C., with protection from atmospheric moisture by CaCl2 tube in N2, thionyl chloride was added dropwise (1.1 ml, 14.1 mmol). The reaction mixture was stirred at 0° C. for 30 minutes and at room temperature for 30 minutes, and then refluxed overnight. The solution was evaporated to dryness in vacuum. The residue was dissolved in absolute ethanol and reevaporated to dryness. To ensure completeness of the esterification, the whole operation was repeated. The ester HLM9 (yellow solid, 1.67 g, 92% yield), which was shown by HPLC to contain about 1% of free amino acid, was further purified by FC(CH2Cl2:MeOH:AcOH 9:1.5:1.5). 1H NMR (250 MHz, D2O) 0.94 (dd, J=7.2, 7.2 Hz, 3H), 3.63 (m, 2H), 4.01 (m, 2H), 4.34 (dd, J=7.7, 7.5 Hz, 1H), 7.31 (d, J=8.0 Hz, 1H), 7.56 (d, J=8.2 Hz, 1H), 8.01 (dd, J=8.7, 5.4 Hz, 1H), 8.93 (d, J=5.4 Hz, 1H), 9.08 (d, J=8.7 Hz, 1H).

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