Kumar, VijaySingh, Praval PratapDwivedi, Ashish RanjanKumar, NaveenRakesh kumar, NoneChandra Sahoo, SubashChakraborty, SudipKumar, Vinod2024-01-212024-08-132024-01-212024-08-132023-06-052046206910.1039/d3ra00773ahttp://10.2.3.109/handle/32116/3316A facile one-step catalyst free methodology has been developed for the regioselective functionalization of 4,6-diphenylpyrimidin-2(1H)-ones under mild conditions. Selectivity towards the O-regioisomer was achieved by using Cs2CO3 in DMF without use of any coupling reagents. A total of 14 regioselective O-alkylated 4,6-diphenylpyrimidines were synthesized in 81-91% yield. In the DFT studies it was observed that the transition state for the formation of the O-regioisomer is more favourable with Cs2CO3 as compared to K2CO3. Furthermore, this methodology was extended to increase the O/N ratio for the alkylation of 2-phenylquinazolin-4(3H)-one derivatives. � 2023 The Royal Society of Chemistry.en-USPotashRegioselectivityCatalyst-freeConditionCoupling reagentsDFT studyFunctionalizationsMechanisticsRegio-selectiveRegioisomersRegioselective functionalizationSynthesisedCesium compoundsArticlehttp://xlink.rsc.org/?DOI=D3RA00773A