Reaction #1884987

Reaction equation

5-bromopentene

cyclopropylamine

→

1a

Yield 60.3%

N-(pent-4-enyl)cyclopropanamine

Yield 60.3%

Solvents

methanol

methanol

Conditions

Workup

1. 1
   Temperaturewas refluxed for 1 h
2. 2
   OtherThe methanol and excess cyclopropylamine were removed by distillation
3. 3
   OtherThe residue, hydrobromide salt of 1a, was partitioned between ether and 4 N NaOH
4. 4
   WashThe aqueous phase was washed with ether (2×)
5. 5
   DryingThe combined ether extracts were dried (MgSO4)
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated

Procedure

Using an addition funnel, a solution of 5-bromopentene (15.8 g, 106 mmol) in 50 mL of methanol was added over the course of 5 min to a solution of cyclopropylamine (20.6 g, 361 mmol) in 200 mL of methanol. The resultant mixture was allowed to stir at rt for 72 h at which time it was refluxed for 1 h. The methanol and excess cyclopropylamine were removed by distillation. The residue, hydrobromide salt of 1a, was partitioned between ether and 4 N NaOH. The aqueous phase was washed with ether (2×). The combined ether extracts were dried (MgSO4), filtered, and concentrated to give 8 g (60%) of 1a as a yellow oil: 1H NMR (500 MHz, CDCl3) δ 0.31-0.36 (m, 2 H) 0.40-0.46 (m, 2 H) 1.53-1.63 (m, 2 H) 1.87 (brs, 1 H) 2.05-2.10 (m, 2 H) 2.10-2.14 (m, 1 H) 2.69 (t, J=7.32 Hz, 2 H) 4.91-5.07 (m, 2 H) 5.72-5.88 (m, 1 H).

Source