Reaction #1256740

Reaction equation

3-cyanobenzoic acid

Borane tetrahydrofuran

→

3-(aminomethyl)benzyl alcohol

Yield 96.3%

3-(Aminomethyl)benzyl alcohol

Yield 96.3%

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   OtherThe reaction was quenched with 220 mL of concentrated HCl:water (1:1)
2. 2
   OtherThe THF was then evaporated off under vacuum
3. 3
   workup.ADDITIONSolid NaOH pellets, 70 g total, were added slowly
4. 4
   ExtractionThe aqueous phase was then extracted 4 times with 500 mL portions of ether
5. 5
   ExtractionThe ether extract
6. 6
   Dryingwas dried over MgSO4
7. 7
   Otherevaporated under vacuum

Procedure

A 20 g sample of 3-cyanobenzoic acid (12) (136 mmol) was suspended in 100 mL of dry tetrahydrofuran (THF). Borane-tetrahydrofuran complex (400 mL of 1.0 M solution in THF) was added dropwise over one hour and then stirred for an additional 3 hours. The reaction was quenched with 220 mL of concentrated HCl:water (1:1) to cleave the borane-alcohol complex. The THF was then evaporated off under vacuum. Solid NaOH pellets, 70 g total, were added slowly to neutralize the acid and bring the pH of the solution to 12. The aqueous phase was then extracted 4 times with 500 mL portions of ether. The ether extract was dried over MgSO4 and evaporated under vacuum to give 18 g (131 mmol) of 3-(aminomethyl)benzyl alcohol (13) as a light colored oil. 1H NMR (CDCl3/TMS) δ=1.95 (broad s, 3H, —OH and —NH2, exchangeable with D2O), 3.86 (s, 2H, —CH2—NH2), 4.66 (s, 2H, —CH2—OH), 7.27 (m, 4H, aromatic).

Source