acetic acid in water 50percent acetic acid for acidifying NaNO2-soln.; removing the products by CO or N2-stream;

HCl or activated silica in tetrahydrofuran THF soln. of excess of Fe complex added to Mn complex, then stirred for16 h at 40°C, filtered, HCl added and stirred for 1 h or mixt. stirred with activated silica; evapd., chromd. (hexane/ether), concd., crystd. (ether/pentane, at -80°C); elem. anal.;

carbon monoxide; hydrogen in tetrahydrofuran Kinetics; byproducts: N-methylpiperidine, ethanol, methane; a mixt. of Fe-complexes in THF was heated at 150°C under 245 atmof 3:1 CO/H2; at 190°C reaction was too fast to monitor;

carbon monoxide; hydrogen in further solvent(s) Kinetics; byproducts: N-methylpiperidine, ethanol, methane; a mixt. of Fe-complexes in N-methylpirrolidinone was heated at 200°C for totally 6 h under 245 atm of 3:1 CO/H2; rate const. is given;