Reacción #2446122

Ecuación de reacción

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

thionyl chloride

ethanol

→

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

Rendimiento 92.0%

Disolventes

N2

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturarefluxed overnight
2. 2
   OtroThe solution was evaporated to dryness in vacuum
3. 3
   workup.DISSOLUTIONThe residue was dissolved in absolute ethanol
4. 4
   Otroreevaporated to dryness
5. 5
   Otrowas further purified by FC(CH2Cl2:MeOH:AcOH 9:1.5:1.5)

Procedimiento

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).

Fuente