[Humr]

Hello. I am preparing for upcoming exam and i would like to ask if somebody know mechanism of this reaction. I dont like hard memorizing things and i would like to understand it.

[Hunter2]

Check keywords  Schiff base, Beckmann conversion, enamine,

[hollytara]

I'm not sure what the "T" over the reaction arrow means....   

I can see the reaction going in acid. 

Protonate the C-N double bond on N.  This generates carbocation on carbon of C double bond,

Carbocation rearranges.  The most stable carbocation has cation adjacent to O.  5 membered ring bond to carbon with hydroxyl breaks and shifts over to the cation C (formerly part of C-N bond).  This new carbocation has the 6 membered ring and the + charge where the OH attaches. 

The OH loses H as H+ and the C=O bond forms. 

[Babcock_Hall]

@OP, In general we expect to see your attempt at solving a problem before we can help you.  You have been given a generous number of hints.

[Humr]

Thanks for suggestions. Explanation by hollytara looks understandable, but it should be done only by heating in decalin. T over arrow means reaction is heated. Also i dont expect to find exact conditions for preparation of ilegal substance.