A One‐Pot Biginelli Synthesis of 6‐Unsubstituted 5‐Aroylpyrimidin‐2(1H)‐ones and 6‐Acetyl‐1,2,4‐triazin‐3(2H)‐ones

Abstract

The three-component Biginelli-like cyclocondensation reaction of enamines 1, urea, and aldehydes in dioxane/acetic acid efficiently afforded the corresponding 6-unsubstituted 3,4-dihydropyrimidin-2(1H)-ones 2 in good yields (Scheme 1, Table). The corresponding reaction of azaenamine (¼ hydrazone) 7 with benzaldehyde and urea afforded 6-acetyl-1,2,4-triazin-3(2H)-ones in good yields (Scheme 3).

Domino Reactions Based on Combinatorial Bond Transformations in Electron-Deficient Tertiary Enamines

“…The structural feature of the DHPMs without C6 substitution synthesized by this enaminone‐based synthesis was notable because it was a recognized challenge to synthesize 6‐unsubstituted DHPMs before this work 20. Following these successful three‐component DHPM‐forming reactions, an otherwise identical reaction using AcOH as catalyst was later reported 21…”

Cytotoxic activity, apoptosis induction and cell cycle arrest in human breast cancer (MCF7) cells by a novel fluorinated tetrahydro-[1,2,4]triazolo[3,4-a]isoquinolin chalcones

“…To expand our previous ndings in the context of our interest in C-C bond formation reactions [11][12][13], as well as in the synthesis of bioactive compounds [14][15][16][17][18], we synthesized herein a novel series of halogenated chalcones and evaluated their cytotoxic activities against cancer cells. Claisen-Schmidt condensation of 3-acetyl-1-aryltetrahydro- [1,2,4]triazolo [3,4-a]isoquinoline 1 [19,20] with the mole equivalents of 4-uorobenzaldehyde 2 in the presence of 20% KOH solution as a basic catalyst resulted in the formation of the corresponding uorinated [1,2,4]triazolo [3,4-a]isoquinoline chalcones 3-8 (Scheme 1).…”

Hantzsch reaction with 6-aminouracil: Synthesis of novel tetrakis(6-aminouracil-5-yl)methanes and bis(decahydropyrido[2,3-d:6,5-d']dipyrimidine-tetraones) linked to aliphatic or aromatic cores via ether-amide or ester-amide linkages

“…18,[37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] Figure 1. Some selected FDA-approved uracil drugs In connection with the importance of both 1,4-dihydropyridine and the dipyrimidine moiety and in continuation to our interest in enamine chemistry, [52][53][54][55][56] the synthesis of bis(heterocycles) 17,[47][48][49][50][51][52][53][54][55][56][57][58][59][60] as well as the C-C bond formation reactions, 52,[71][72][73] we report herein a highly efficient method for the synthesis of bis(pyrido [2,3-d:6,5-d']dipyrimidinetetraones) linked to aliphatic or aromatic core via ether-amide or esteramide linkages through the reaction of bis(aldehydes) with 6-aminouracil.…”