تفاعل #460834

معادلة التفاعل

N-Cbz-L-phenylalanine

benzaldehyde

p-toluenesulfonic acid

→

crystals

المردود 12.4%

(2S,4S)-3-Benzyloxycarbonyl-2-phenyl-4-phenylmethyl-5-oxooxazolidine

المردود 12.4%

المذيبات

1,1,1-trichloroethane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe solution was refluxed for 18 hr
2. 2
   أخرىthe water was removed by azeotropic distillation
3. 3
   درجة الحرارةAfter cooling
4. 4
   غسيلthe reaction was washed with saturated aqueous NaHCO3 (3×50 ml), water (1×50 ml)
5. 5
   تجفيفdried over sodium sulfate
6. 6
   تركيزconcentrated in vacuo
7. 7
   أخرىto produce an orange oil
8. 8
   أخرىAfter about 1 h a solid crystallized from the oil and it
9. 9
   ترشيحwas collected by vacuum filtration
10. 10
    أخرىThe orange solid was recrystallized from ethyl acetate/hexane

الإجراء التجريبي

Following the procedure of Karady, Tett. Lett., 1984, 25:4337. N-Cbz-L-phenylalanine (25 g, 83.5 mmol), benzaldehyde (18 g, 170 mmol), and p-toluenesulfonic acid (11.2 g, 58 mmol) were suspended in 1,1,1-trichloroethane (300 ml). The solution was refluxed for 18 hr and the water was removed by azeotropic distillation using a Dean-Stark trap for liquids heavier than water. After cooling, the reaction was washed with saturated aqueous NaHCO3 (3×50 ml), water (1×50 ml), dried over sodium sulfate and concentrated in vacuo to produce an orange oil. After about 1 h a solid crystallized from the oil and it was collected by vacuum filtration. The orange solid was recrystallized from ethyl acetate/hexane to produce colorless crystals (4.0 g, 12%); mp 120°-122° C. MS (CI): 405 (M+NH4)+, 388 (M+H)+.

المصدر