Synthesis of Pyrimidines and Heteroannulated Pyrimidine Ring Systems

Abstract

ABSTRACT. We have involved the imine compound 1 in condensations with various nitrogenous reagents including hydrazine hydrate to construct differently substituted pyrimidines. One of the pyrimidines so obtained was further subjected to interactions with different reagents such as propionic acid, formic acid, ethyl chloroformate, acdetic anhydride, carbon disulphide, cyanogene bromide, triflauroacetic acid and ethyl chloroacetate which resulted in the formation of annulated heterocyclic systems as pairs of isomers in most cases as a result of Dimroth-type rearrangement.

Design and Synthesis of Novel N-Benzylidene Derivatives of 3-Amino-4-imino-3,5-dihydro-4H-chromeno[2,3-d]pyrimidine under Microwave, In Silico ADME Predictions, In Vitro Antitumoral Activities and In Vivo Toxicity

“…The interest of this method is that compound 6 is not soluble in the reaction mixture, which facilitates recovery using simple filtration. For the aza-annulation of imidate 6 into 4-imino-4,5-dihydro-3 H -chromeno[2,3- d ]pyrimidine 8 , we applied a method described in the literature [ 21 ] employing the hydrazine reagent 7 . Applying this approach with slight experimental modifications, we treated imidate 6 with 1.6 equivalents of aqueous solution of hydrazine (35% w / v ) at room temperature in EtOH for 2 h. As the reaction progressed, we noticed the low solubility of 3-amino-4-imino-3,5-dihydro-4 H -chromeno[2,3- d ]pyrimidine 8 in the reaction media which, again, facilitates their recovery by simple filtration.…”

3-Amino-8-hydroxy-4-imino-6-methyl-5-phenyl-4,5-dihydro-3H-chromeno [2,3-d ]pyrimidine: An Effecient Key Precursor for Novel Synthesis of Some Interesting Triazines and Triazepines as Potential Anti-Tumor Agents

“…The title compound 1 was prepared according to the procedure reported in literature [ 10 ], and it was proved to be highly reactive towards various reagents, resulting in the formation of a wide range of annulated chromenopyrimidine systems. With compound 1 in hand, a number of valuable heterocycles could be prepared.…”

“…Antitumor activity was evaluated by the Regional Center for Mycology and Biotechnology, Al-Azhar University, Cairo, Egypt. 3-Amino-8-hydroxy-4-imino-6-methyl-5-phenyl-4,5-dihydro-3 H -chromeno[2,3-d]pyrimidine ( 1 ) [ 10 ] and hydrazonoyl halides 2 [ 26 , 27 ] were prepared as reported in the literature.…”

“…It was reported that pyrimidotriazines themselves posses biological activities with a wide range of applications [ 5 , 6 , 7 , 8 , 9 ]. The research done in this article could be regarded as an extension to our previous work [ 10 ] for constructing fused chromenopyrimidines heterocycles through reactions of the key compound 1 with a variety of reagents, especially hydrazonyl halides [ 11 , 12 , 13 , 14 ], which lead to interesting azoheterocyclic compounds.…”