One-pot synthesis of 4-aminated pyrrolo[2,3-d]pyrimidines from alkynylpyrimidines under metal-catalyst-free conditions

A Strategy for the Triarylation of Pyrrolo­pyrimidines by Using Microwave‐Promoted Cross‐Coupling Reactions

“…5‐Alkynylpyrimidine 5 was then prepared by the direct and regioselective substitution of 2 using methylamine followed by iodination at the C‐5 position of 4‐chloro‐6‐(methylamino)‐2‐(methylthio)pyrimidine ( 3 ) using N ‐iodosuccinimide (NIS) and then a Sonogashira‐type alkynylation by using phenylacetylene under microwave irradiation. The last step involves an intramolecular cyclization of acetylene derivative 5 to give 6‐arylated deazapurine 6 under conditions that we previously established for related compounds 13. Our synthetic route towards target 6 included a combination of these five steps with an overall yield of 70 % (Scheme ).…”

“…The last step involves an intramolecular cyclization of acetylene derivative 5 to give 6-arylated deazapurine 6 under conditions that we previously established for related compounds. [13] Our synthetic route towards target 6 included a combination of these five steps with an overall yield of 70 % (Scheme 1). Scheme Considering the attraction of a concise and rapid synthetic procedure that would allow the preparation of a series of 2,4,6-trisubstituted pyrrolopyrimidines, we were primarily interested in the arylation of heterocyclic intermediate 6.…”

“…In previous reports related to the synthesis of pyrrolopyrimidines, we employed stepwise arylations at the C-4 and C-5 positions of 6-aryl-4,6-dihalopyrrolo [2,3-d]pyrimidines, [12] and more recently, we reported details of a one-pot synthesis of 4,6-disubstituted pyrrolopyrimidines. [13] The substitution of pyrrolopyrimidines is often difficult to control, and selectivity plays an special role when different substituents need to be introduced. [14] In this current work, a more selective strategy was developed to obtain 2,4,6-triarylpyrrolo [2,3-d]pyrimidines from 4-chloro-7-methyl-2-(methylthio)-6-phenylpyrrolo [3,2-d]pyrimidines.…”

Two‐Step Regioselective Synthesis of 3‐(Sulfonylamino)imidazo[1,2‐a]pyrimidines from 2‐Aminopyrimidines and N‐(2,2‐Dichloro‐2‐phenylethylidene)arensulfonamides

“…In this work related to Suzuki–Miyaura and Liebeskind–Srogl couplings as well as in previous studies,12,13 we have used microwave irradiation. The use of microwave irradiation as opposed to conventional heating significantly increases the yield and accelerates the rate of a reaction.…”

“…In previous reports related to the synthesis of pyrrolopyrimidines, we employed stepwise arylations at the C‐4 and C‐5 positions of 6‐aryl‐4,6‐dihalopyrrolo[2,3‐ d ]pyrimidines,12 and more recently, we reported details of a one‐pot synthesis of 4,6‐disubstituted pyrrolopyrimidines 13. The substitution of pyrrolopyrimidines is often difficult to control, and selectivity plays an special role when different substituents need to be introduced 14…”