MUMBAI, India, Nov. 2 -- Intellectual Property India has published a patent application (202611116285 A) filed by L Raju Chowhan; and Jawaharlal Nehru University on September 29, 2026, for A Photoacid-Catalyzed One-Pot Process For The Synthesis Of Functionalized Pyrazolo[3,4-B]pyridine And Pyrido[2,3-D]pyrimidine Derivatives.
Inventors include L Raju Chowhan; and Biplob Borah.
The application for the patent was published on October 30, 2026, under issue no. 44/2026.
Abstract: The present invention relates to a visible-light-induced photoacid-catalyzed one-pot process for the synthesis of functionalized fused nitrogen heterocycles. The process employs Schreiner's thiourea as an organocatalytic photoacid system which, under visible-light irradiation, generates an active acidic catalytic species in situ. In one embodiment, substituted 3-formylchromones are reacted with substituted pyrazoles in 1,4-dioxane under blue LED irradiation to afford functionalized pyrazolo[3,4- b]pyridine derivatives. In another embodiment, substituted 3-formyl chromones are reacted with 6-amino uracils to provide pyrido[2,3-d]pyrimidine derivatives. A further embodiment employs 6-amino-2,4-dihydroxypyrimidine to provide corresponding 2,4-dihydroxypyrido[2,3-d]pyrimidines. Representative disclosed conditions employ about 10 mol% Schreiner's thiourea, dioxane and 40 W blue LED irradiation at about 450 nm under mild temperature conditions. The process provides a one- pot route to functionalized heterocycles without requiring externally added strong Brønsted acids or transition-metal catalysts in the disclosed embodiments.
Disclaimer: Curated by HT Syndication.
