Scheme 1.

Synthesis of GLP‐1R prearranged PAMs. a) BMTP is obtained after a two‐step synthetic sequence from commercially available boronic ester 1 and chloropyrimidine 2 after Pd cross‐coupling and subsequent monooxidation. b) Wittig transformation gives access to trans‐ and cis‐stilbenes that can be separated by FCC and independently processed towards thioether 8. trans‐ and cis‐SMTP are obtained as the monooxidized products from 8, whereas bisoxidation, aromatic substitution, and monooxidation yield the prearranged positive allosteric modulators trans‐ and cis‐SETP. c) Crystal structure of BETP.