dormouse (Member)
04-19-00 11:47
No 122753
      A synthetic challenge: THIQ chemistry  Bookmark   

Author Topic:   A synthetic challenge: THIQ chemistry
drone 342
Member posted 09-14-98 08:36 PM          
As most of you probobly know, tetrahydroisoquinolines are a group of chemicals that haven't been given as much study as they ought to from an entheogenic standpoint. Many of the naturally occuring analogs are found within the human body, and have a pharmacology far different from anything else encountered. From a pharmacological point of view, they are particularily fascinating in the sense that they are a sort of chemical overlap of the opiates and the PEA's. Here's my query:
How would one produce them without using PEA's? I've found several efficient routes that have PEA's as intermediates, but how would one accomplish the synthesis of THIQ's without going through that particular class of chemicals?

-drone #342

Administrator posted 09-14-98 10:55 PM          
The only way I can think of right now would be by cyclizing the ortho-amino derivative of a 3-chloro propiophenone, but that's kinda obvious, as well as not that practical...

beagle boy
unregistered posted 09-15-98 11:40 AM           
Yep, best ways to THIQ's is through PEA's. Pictet-Gams synth constructs a 2-alkyl isoquinoline which could be reduced to THIQ: acetophenone + HONO goes to alpha-OH PEA. Reaction w/ acid halide gives the isoquinoline. And as long as you have that hydroxy PEA, why not dream up some aminorex deriv's.

Pomeranz-Fritsch synth reacts a benzaldehyde w/ aminoacetaldehyde diethyl acetal to give an imine. Imine is cyclized w/ H2SO4 to get quinoline. Yields variable, need e- releasing subst. on benzaldehyde.

Have any targets in mind?

Rho: That amino propriophenone above would give a quinoline rather than isoquinoline.