Tetracyclic 6 azapyrazinoindolines as 5HT2C receptor agonists for obesity

A compound of formula

• wherein
• R1 and R2 form together with the carbon atoms Ca and Cb to which they are attached
• R3 is hydrogen, alkyl or cycloalkyl;
• R4 is hydrogen, alkyl, cycloalkyl, alkylcarbonyl or cycloalkylcarbonyl;
• R5 is alkyl or cycloalkyl;
• R6 and R7 are independently selected from hydrogen, alkyl, cycloalkyl, hydroxyalkyl and alkoxyalkyl;
• R8 and R9 are independently selected from hydrogen, alkyl, cycloalkyl, hydroxyalkyl and alkoxyalkyl;
• R10 and R11 are independently selected from hydrogen and alkyl;
• and
• R12 and R13 are independently selected from hydrogen and alkyl;
• or pharmaceutically acceptable salts and esters thereof.