Реакция #350892

Уравнение реакции

methyl 1-[(S)-3-(benzyloxycarbonyl)-2-(trifluoroacetylamino)propionyl]-2,3-dihydroindole-2-(S)-carboxylate

→

methyl 1-[(S)-3-carboxy-2-(trifluoroacetylamino)-propionyl]-2,3-dihydroindole-2-(S)-carboxylate

Растворители

ethyl acetate

Условия реакции

Обработка

1. 1
   ФильтрацияThe catalyst is filtered off
2. 2
   Концентрированиеthe filtrate is concentrated under reduced pressure
3. 3
   ДругоеThe residue is partitioned between ether (350 mL) and water (100 mL)
4. 4
   ПромывкаThe organic layer is washed successively with 1N HCl (100 mL) and water (2×100 mL)
5. 5
   Сушкаdried over anhydrous sodium sulfate
6. 6
   Фильтрацияfiltered
7. 7
   Фильтрацияfiltered through a thin layer of silica gel (flash grade)
8. 8
   ПромывкаThe product is eluted with ether (200 mL)
9. 9
   ДругоеThe solvent is evaporated under reduced pressure
10. 10
    Другоеthe residue crystallized from ether-hexane (1:1)
11. 11
    ДругоеThe white crystals are collected
12. 12
    Другоеdried under high vacuum for 1 hour at 40° C.

Методика

A solution of methyl 1-[(S)-3-(benzyloxycarbonyl)-2-(trifluoroacetylamino)propionyl]-2,3-dihydroindole-2-(S)-carboxylate (30.1 g, 63 mmol) in ethyl acetate (450 mL) is hydrogenated on the Parr apparatus at 50 psi in the presence of 10% palladium on carbon (15 g) for 105 minutes. The catalyst is filtered off and the filtrate is concentrated under reduced pressure. The residue is partitioned between ether (350 mL) and water (100 mL). The organic layer is washed successively with 1N HCl (100 mL) and water (2×100 mL), then dried over anhydrous sodium sulfate and filtered. The filtrated is decolorized with charcoal, then filtered through a thin layer of silica gel (flash grade). The product is eluted with ether (200 mL). The solvent is evaporated under reduced pressure and the residue crystallized from ether-hexane (1:1). The white crystals are collected and dried under high vacuum for 1 hour at 40° C., then for 18 hours at room temperature to yield methyl 1-[(S)-3-carboxy-2-(trifluoroacetylamino)-propionyl]-2,3-dihydroindole-2-(S)-carboxylate, m.p. 157°-158° C.; [α]D =-188.76 (CHCl3, c 1.1).

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