Reaktion #1256739

Reaktionsgleichung

sulfuric acid

LiAlH4

H2SO4

4-Cyanobenzoic acid

→

4-(aminomethyl)benzyl alcohol

Ausbeute 70.6%

4-(Aminomethyl)benzyl alcohol

Ausbeute 70.6%

Lösungsmittel

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added dropwise
2. 2
   TemperaturThe reaction was heated
3. 3
   Temperaturto reflux for 4 hours
4. 4
   SonstigeThe reaction was quenched on ice with 215 mL of water
5. 5
   workup.ADDITIONfollowed by the addition of 80 g of NaOH in 650 mL of water
6. 6
   SonstigeThe ether was decanted off the resulting gel
7. 7
   Extraktionthe gel was extracted twice with 600 mL portions of ether
8. 8
   TrocknenThe combined ether fractions were dried over MgSO4
9. 9
   Sonstigeevaporated under vacuum

Vorschrift

Adapting the procedure described by Keppler et al., Nature Biotechnology 21, 86-89 (2003), 1.5 L of 0.5 M LiAlH4 were chilled on ice and 22 mL of concentrated H2SO4 were added dropwise. 4-Cyanobenzoic acid (10) 20 g (136 mmol) was suspended in 120 mL of ether and this was added dropwise to the sulfuric acid. The reaction was heated to reflux for 4 hours. The reaction was quenched on ice with 215 mL of water followed by the addition of 80 g of NaOH in 650 mL of water. The ether was decanted off the resulting gel and the gel was extracted twice with 600 mL portions of ether. The combined ether fractions were dried over MgSO4 and evaporated under vacuum to give 13.1 g (96 mmol) of 4-(aminomethyl)benzyl alcohol (11) as a clear oil. 1H NMR (CDCL3/TMS) δ=1.95 (broad s, 3H, —OH and —NH2, exchangeable with D2O), 3.86 (s, 2H, —CH2—NH2), 4.68 (s, 2H, —CH2—OH), 7.30 (m, 4H, aromatic).

Quelle