Synthesis of new‐type 1,3,6‐triazocine via intramolecular reactions of iodocyclization and [3+2] azido cycloaddition

Abstract

Selective iodocyclization of 6‐(alkenylamino)‐1‐allylpyrazolo[3,4‐d]pyrimidines provided hydrogenated derivatives of 1‐allyl‐8(9)‐iodomethylimidazo(pyrimido)[1,2‐a]pyrazolo[4,3‐e]pyrimidines which were further reacted with NaN3 at 75°С to 80°С to give a series of new‐type 1,3,6‐triazocines annulated with the pyrazole, pyrimidine, imidazole (or pyrimidine), and 1,2,3‐triazole rings. The compounds synthesized were structurally characterized by analytical, spectral (IR, 1H and 13C NMR, HPLC‐mass), and X‐ray diffraction data.

Cyclizations of Alkenyl(Alkynyl)‐Functionalized Quinazolinones and their Heteroanalogues: A Powerful Strategy for the Construction of Polyheterocyclic Structures

“…A number of studies have been reported on the cyclization of 2‐allyl(cinnamyl)pyrimidin‐4(3 H )‐ones 71 by the action of electrophilic reagents such as iodine and arylsulfenyl chlorides (Scheme 20). [103–108] As shown, these substrates cyclize like their alkenylthio analogues, via the 5‐ exo‐trig or 6‐ endo‐trig mode involving the pyrimidine N1 atom, to produce angular imidazo‐ or pyrimidopyrimidinones 75 – 77 . The only exception is represented by cinnamylaminopyrido[3,4‐ d ]pyrimidinone 71 d , which undergoes cyclosulfenylation to linear product 78 [109] …”

“…[103,104] A number of studies have been reported on the cyclization of 2-allyl(cinnamyl)pyrimidin-4(3H)-ones 71 by the action of electrophilic reagents such as iodine and arylsulfenyl chlorides (Scheme 20). [103][104][105][106][107][108] As shown, these substrates cyclize like their alkenylthio analogues, via…”