Allylamine → Allyl-(2-methyl-pent-4-enyl)-amine

Participants

Reaction Steps

To a solution of 2-methyl-pent-4-enoic acid ethyl ester (7.1 g, 50 mmol) was added dropwise a solution of DIBAL (1.0 M in hexanes, 75 ml) at −78 C. over 1.0 h. After the addition, the reaction mixture was stirred at −78 C. for another hour. The reaction was quenched with saturated NH4Cl (10 ml) and 4% HCl, then was extracted with EtOAc (3×100 ml). The combined organic extracts were dried with MgSO4, filtered, concentrated by rotary evaporation and the crude reaction product was used in the next reaction without further purification. 2-Methyl-4-pentenal (3.3 g, 33.7 mmol) was dissolved in CH2Cl2 (100 ml). To this solution allylamine (2.9 g, 50.5 mmol) was added. Molecular sieves (5 g) were used to absorb water generated during the reaction. The mixture was stirred at room temperature over night. The reaction mixture was concentrated by rotary evaporation and the crude product was used in the next reaction without further purification. Allyl-(2-methyl-pent-4-enylidene)-amine (3.2 g, 23.4 mmol) was diluted in 50 ml MeOH. To the solution NaBH4 (1.0 g, 26.3 mmol) was added at 0° C. After addition the mixture was stirred at RT for 5 h. The reaction mixture was concentrated and the residue was partitioned between EtOAc/20% aq. NaOH. The organic layer was dried over Na2SO4, fitered and concentrated by rotary evaporation to give allyl-(2-methyl-pent-4-enyl)-amine (1.5 g 48% yield): 1H-NMR (400 Hz, CDCl3): d=5.93–5.68 (m, 2H), 5.18–4.92(m, 4H), 3.21 (d, 2H), 2.60–2.40(m, 2H), 1.97–1.65(m, 2H), 0.92(d, 3H).

Provenance & Evidence