[Mpatas]

I used a reduction method going from pyridine to piperidine using 3 bar H2 and PtO2 in ethanol : chloroform in a ratio of 10:1 and at the end i get the HCL salt.Can someone explain me the mechanism of that or give me a hint?I know that that oxidizing Chloroform gives phosgene and HCL.

[AlphaScent]

Chloroform will surely react to form HCl and dichlorocarbene.  If the platinum oxide reacts at all to form diatomic oxygen in situ you will yield phosgene. 

You answered your own question, though.  You were missing where the HCl came from.  It is from chloroform.

Look up the mechanism to dichlorocarbene formation.  You will have your complete answer.

[Mpatas]

There is no possibility that chloroform is reduces as well to givei CH2Cl2 and HCl?

[AlphaScent]

At 3 bar.  No.  Chloroform will not be reduced to DCM.  The pKa of piperidine is 11.  Do you think this is basic enough to remove the proton from chloroform to form dichlorocarbene and HCl??