KatB's blog

28 Mar

Update on the LA catalysed PS reaction

Published by KatB

It's now been about 3 weeks since I started working on the Lewis Acid (LAs) catalysed Pictet-Spengler project (see first post here). So far, I've been working on preparing the imine starting materials (1a-d) and getting them to cyclise (2a-d), just so I have a final product reference and a starting point for developing an assay to monitor the reaction.

12 Mar

Lewis Acid Catalysed Pictet-Spengler Reaction Model

Published by KatB

Over the next 12 weeks I will be working on a model system for the Lewis Acid catalysed Pictet-Spengler formation of substitued tetrahydroisoquinolines (e.g. 4).

After making the starting materials (3, R1 = H, OMe and R2 = H, NO2, OMe) I'll work on screening various Lewis Acids with a focus on silver(I) triflate, given recent results - see AgOTf post here.

29 Feb

Silver(I) Triflate Catalysed PS Reactions

Published by KatB

Before I started on the triflic acid catalysed Pictet-Spengler reactions (see here), I was working on the silver(I) triflate catalysed reactions.

28 Feb

Triflic Acid Catalysed PS Reactions

Published by KatB

The use of catalytic triflic acid TfOH in the Pictet-Spengler reaction was initially performed as a control for the silver(I) triflate (AgOTf) catalysed reaction (here). All early experiments using TfOH were performed with the dimethoxy N-benzoyl PZQ analogue and catalyst loading was reduced down to 5% (KAB8-7 & KAB8-8, KAB8-9).

27 Dec

Puzzled over MS

Published by KatB

Subject 

Rants, Miscellaneous

Background
Relevant experiment.  Basically, the Pictet-Spengler to form 3 PZQ analogues and PZQ itself.
The mass spec is of a by-product of the acid mediated PS cyclisation of MNR10-1 to form KAB8-1, aka the dimethoxy N-benzoyl PZQ analogue.

02 Dec

Two weeks in the PZQ lab

Published by KatB

Subject 

Rants, Miscellaneous

 
I've now reached the end of my second week in the lab working on the Pictet-Spengler route to praziquantel.