Reaktion #10659

Reaktionsgleichung

Intermediate 35

trans-4-(N-tert-butoxycarbonylamino)cyclohexanol

1,1′-azobis(N,N-dimethylformamide)

p-anisic acid

tri(n-butyl)phosphine

→

title compound

Ausbeute 96.3%

cis-4-methoxybenzoic acid 4-(tert-butoxycarbonylamino)cyclohexyl ester

Ausbeute 96.3%

Lösungsmittel

ethyl acetate

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was cooled to room temperature
2. 2
   Waschensuccessively washed with saturated aqueous sodium hydrogencarbonate twice (200 ml each) and 0.1 N aqueous sodium hydroxide (50 ml)
3. 3
   Trocknendried over anhydrous sodium sulfate
4. 4
   SonstigeThe solvent was evaporated under reduced pressure
5. 5
   Sonstigethe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=5:1)

Vorschrift

A solution of Intermediate 35 (21.06 g), 1,1′-azobis(N,N-dimethylformamide) (64.11 g) and p-anisic acid (23.03 g, Tokyo Kasei Kogyo) in tetrahydrofuran (400 ml) was added with tri(n-butyl)phosphine (35.6 ml) at room temperature and stirred at 50° C. for 2.5 hours. The reaction mixture was cooled to room temperature, then added with ethyl acetate (200 ml) and successively washed with saturated aqueous sodium hydrogencarbonate twice (200 ml each) and 0.1 N aqueous sodium hydroxide (50 ml), and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=5:1) to obtain the title compound (32.92 g).

Quelle