تفاعل #2446122

معادلة التفاعل

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

thionyl chloride

ethanol

→

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

المردود 92.0%

المذيبات

N2

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةrefluxed overnight
2. 2
   أخرىThe solution was evaporated to dryness in vacuum
3. 3
   workup.DISSOLUTIONThe residue was dissolved in absolute ethanol
4. 4
   أخرىreevaporated to dryness
5. 5
   أخرىwas further purified by FC(CH2Cl2:MeOH:AcOH 9:1.5:1.5)

الإجراء التجريبي

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).

المصدر