Scheme 3. Synthesis of Analogues Based on PAT Template.

Reagents and conditions: (a) BrCN, Et₂O/hexane; (b) CH₃SO₃H, EtOH, reflux, 24 h; (c) (1) 6 M HCl, (2) NaOH 25% conc.; (d) PhSO₂Cl, Et₃N; (e) −78 °C, t-BuLi, 3,4,5-trimethoxybenzoyl chloride; (f) Boc₂O, NaOH; (g) (chloromethanetriyl)tribenzene, Et₃N, CH₂Cl₂; (h) HCl; (i) H₂, Pd–C, 5%, EtOH, 40 psi; (j) PhCOSCN, Me₂CO; (k) MeOH, 1 N NaOH; (l) EtOH, 65 °C; (m) NaOH, MeOH; (n) HBTU, NMM, HNCH₃OCH₃·HCl, CH₂Cl₂; (o) 3,4,5-trimethoxyphenylbromide, n-BuLi, THF.