An efficient one-pot protocol for the solvent-free synthesis of novel quinoline-3-thiocarboxamide and 2,3-dihydroquinazolin-4(1H)-one derivatives

Recent developments in the solvent-free synthesis of heterocycles

“…In 2017, S. R. Narra et al published a solvent-free one-pot synthesis of quinoline 121 and quinazoline 122 derivatives (Scheme 34). 51 In this reaction 3-oxo- N ,3-diphenylpropanethioamide 119 , and 2-aminobenzoketone 120 /2-aminobenzoester 120′ were used as starting materials, and the reaction condition was optimized using 10 mol% of InCl 3 as the catalyst at 80 °C under microwave irradiation. Initially, InCl 3 catalyzed Knoevenagel condensation of 2-aminophenylketones 120 with the active methylene group of N -aryl-mercapto-aminoketone 119 formed intermediate 120ab , which cyclized to stable substituted quinoline-3-thiocarboxamides 121 .…”

Crystal structure, Hirshfeld surface analysis and energy framework study of 6-formyl-7,8,9,11-tetrahydro-5H-pyrido[2,1-b]quinazolin-11-one

“…A search in the Cambridge Structural Database (CSD, version 5.41, update January 2020; Groom et al, 2016) revealed six matches for molecules containing the 3-methyl-2-(propan-2ylidene)-2,3-dihydroquinazolin-4(1H)-one moiety with a similar planar conformation to that in the title structure: Duke & Codding, 1993) and (E)-2-[2-oxo-2-(thiophen-2-yl)ethylidene]-3-phenyl-2,3-dihydroquinazolin-4(1H)-one (SATJOP; Narra et al, 2017). A search for the 2-amino-1,4,5,6-tetrahydropyridine-3-carbaldehyde moiety gave one hit with similar conformation: 1-methyl-2-(methylamino)-1,4,5,6-tetrahydropyridine-3-carbaldehyde (MFHPYM10; Horvá th et al, 1983).…”

Trifluoroborane catalyzed chemoselective synthesis of highly functionalized 1,3‐thiazin‐2‐ylidenes

“…[ 18–22 ] The established methods, however, suffered some drawbacks like limited functional group tolerance or hardly available starting materials. Based on the previous reports [ 23–25 ] on the functions of 3‐oxo‐ N , 3‐diarylpropanethioamide in multicomponent reactions for constructing diverse structural motifs, herein, we report the first instance of highly chemoselective preparation of functionalized 1,3‐thiazine‐2‐ylidenes via domino annulation of N, S ‐keteneacetals with propargyl alcohols in the presence of BF 3 OEt 2 at room temperature.…”