Reaction #792141

Reaction equation

sodium cyanoborohydride

acetic acid

1-(indan-2-yl)ethanone

cyclopropylamine

→

N-[1-(indan-2-yl)ethyl]cyclopropanamine

Yield 28.0%

Solvents

methanol

Conditions

Workup

1. 1
   Temperatureat reflux
2. 2
   workup.STIRRINGthe reaction mixture is further stirred for 2 hrs
3. 3
   Temperatureat reflux
4. 4
   OtherThe cooled reaction mixture
5. 5
   Filtrationis then filtered over a cake of diatomaceous earth
6. 6
   WashThe cake is washed twice by 80 ml of methanol
7. 7
   Concentrationthe combined methanolic extracts are concentrated under vacuum
8. 8
   workup.ADDITION100 ml of water are then added to the residue
9. 9
   ExtractionThe watery layer is extracted with 300 ml of ethyl acetate
10. 10
    WashThe organic layer is washed twice by brine
11. 11
    Filtrationfiltered over a phase separator paper
12. 12
    Otherto yield after concentration 5 g of a yellow oil

Procedure

To a cooled solution of 3.5 g (21.8 mmol) of 1-(indan-2-yl)ethanone in 100 ml of methanol, are added 10 g of 3 Å molecular sieves and 2.3 g (40.2 mmol) of cyclopropylamine followed by a slow addition of 2.87 ml (50.2 mmol) of acetic acid. The reaction mixture is stirred for 2.5 hrs at reflux. The reaction mixture is then cooled to 0° C. and 1.9 g (30 mmol) of sodium cyanoborohydride are slowly added and the reaction mixture is further stirred for 2 hrs at reflux. The cooled reaction mixture is then filtered over a cake of diatomaceous earth. The cake is washed twice by 80 ml of methanol and the combined methanolic extracts are concentrated under vacuum. 100 ml of water are then added to the residue and the pH is ajusted to 12 with a 0.5 N solution of sodium hydroxyde. The watery layer is extracted with 300 ml of ethyl acetate. The organic layer is washed twice by brine and filtered over a phase separator paper to yield after concentration 5 g of a yellow oil. Column chromatography on silica gel (gradient heptane/ethyl acetate) yields 1.2 g (28% yield) of N-[1-(indan-2-yl)ethyl]cyclopropanamine as a colourless oil (M+H =202).

Source