# Can anyone explain the reaction mechanism of these two synthesis?

Can anyone explain the reaction mechanism of the two synthesis given below ?

$\ce{Ar-NO2 ->[\ce{H2/Pd}][\ce{EtOH}] Ar-NH2}$

$\ce{Ar-NO2 ->[\ce{Sn + HCl} \text{ or } \ce{Fe + HCl}] Ar-NH2}$

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What are your own thoughts on the matter? Do you have done any research or have any clue what might happen? – Philipp Jul 30 '14 at 16:22