[Nescafe]

Hello,

I am struggling to get the reaction to proceed between an aniline with electron withdrawing groups and a ketone (hexanone). Weird thing is that the first time I did it in MeOH, AcOH and Sodium cyanoborohydride at 50C I got a 50% yield but now am only getting 10% at a larger scale.

Does anyone have advice or any tricks I could use?

Sina.

[kamiyu]

1) Reproducibility on larger scale is often a problem. Also, pay a special attention on the safety. I think this kind of reaction is exothermic in nature. Don't get it overheated

2) I had experience in redctive amination before. My experience is that this reaction is time-sensitive. If you did it for a prolonged stirring, the yield drops A LOT.

[discodermolide]

Acetic acid has a reasonable heat capacity, 123.1 J/(mol K), so it should not matter too much if the reaction gets warm, I doubt it will reach the boiling point of 118°C. That is assuming you have enough of it as a solvent.