Reaktion #449965

Reaktionsgleichung

intermediate ( 5 )

(±)-cis-1-[(1,1-dimethylethoxy)carbonyl]-3-methoxy-4-piperidinyl 4-amino-5-chloro-2,3-dihydro-7-benzofurancarboxylate

NH4OH

→

(±)-cis-3-methoxy-4-piperidinyl 4-amino-5-chloro-2,3-dihydro-7-benzofurancarboxylate

Ausbeute 26.1%

Lösungsmittel

tetrahydrofuran

hydrochloric acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturrefluxed for 30 minutes
2. 2
   TemperaturThe reaction mixture was cooled
3. 3
   SonstigeThe layers were separated
4. 4
   ExtraktionThe aqueous layer was extracted with tetrahydrofuran
5. 5
   SonstigeThe separated organic layer was evaporated
6. 6
   SonstigeThe residue was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 93/7)
7. 7
   SonstigeThe pure fractions were collected
8. 8
   Sonstigethe solvent was evaporated
9. 9
   SonstigeThe residue was crystallized from acetonitrile
10. 10
    FiltrationThe precipitate was filtered off
11. 11
    Sonstigedried (vacuum; 80° C.)

Vorschrift

A mixture of intermediate (5) (32 g) in tetrahydrofuran (500 ml) and hydrochloric acid (50 ml) was stirred and refluxed for 30 minutes. The reaction mixture was cooled and alkalized with NH4OH. The layers were separated. The aqueous layer was extracted with tetrahydrofuran. The separated organic layer was evaporated. The residue was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 93/7). The pure fractions were collected and the solvent was evaporated. The residue was crystallized from acetonitrile. The precipitate was filtered off and dried (vacuum; 80° C.), yielding 6.4 g of (±)-cis-3-methoxy-4-piperidinyl 4-amino-5-chloro-2,3-dihydro-7-benzofurancarboxylate (26%) (intermediate 6).

Quelle