Tryptamine Prodrugs

Abstract

The present invention provides a tryptamine prodrug compound. A compound represented by the formula (I)where each symbol is as described in the specification, or a salt or zwitterion thereof, is converted to an active which has 5HT2A receptor agonist activity, and is useful as an agent for the treatment of depression.

What is claimed is: 
     
         1 . A compound of Formula (I) (II), (III) or (IV) or a pharmaceutically acceptable salt or zwitterion thereof: 
       
         
           
           
               
               
           
         
         wherein: 
         (1) R1, R2, and R6 are each independently selected from hydrogen, linear or branched alkyl, or arylalkyl; 
         (2) R4 is
 a. —X—CO2H, where X is a linear, cyclic or branched, saturated or unsaturated carbon chain, optionally substituted with —OH or —CO2H; or an aromatic ring, optionally substituted with alkyl or CO2H; or 
 b. 
 
       
       
         
           
           
               
               
           
         
       
       wherein R9 is X—CO2H, where X is as defined in (2)(a) above and R10 is hydrogen, linear or branched alkyl or arylalkyl, optionally substituted by —OH or —CO2H;
 (3) R5 is hydrogen, linear or branched alkyl, arylalkyl, or O—R5′, where R5′ is hydrogen, linear or branched alkyl; and 
 (4) R7 and R8:
 a. are each independently selected from hydrogen, linear or branched alkyl, or arylalkyl, or 
 b. together form a non-aromatic N-containing heterocycle, optionally substituted with alkyl.