A concise, facile and MCR-GAP chemistry strategy for the synthesis of spiro[benzo[4,5]thiazolo[3,2-a]pyrano[2,3-d]pyrimidine-4,3′-indoline] derivatives as fluorescent cellular imaging agents

Recent advancements in the multicomponent synthesis of heterocycles integrated with a pyrano[2,3-d]pyrimidine core

“…Gholami et al 132 have specified the synthesis of spiro[benzothiazolo-pyranopyrimidine-indolines] 64 by multicomponent one-pot reactions of isatins with active methylene compounds, i.e. , malononitrile or alkyl 2-cyanoacetates, and 4 H -benzothiazolo-pyrimidinone in ethanol/trimethylamine at reflux temperature ( Scheme 36 ).…”

“…The mechanism of the formation of this class “spirooxoindoles” is complemented with the same sequence of the aforementioned spiro[benzothiazolopyranopyrimidine-indolines]. 132 …”

“…compounds 58a, 58e, 58h, 58i, 58j, and 58k achieved signicantly analogous binding marks and modes of interaction than N3, demonstrating a hopeful tendency concerning SARS-CoV-2 M pro with the expectation to cover the approach for the detection of anti-SARs-CoV-2 drugs. Gholami et al 132 have specied the synthesis of spiro [benzothiazolo-pyranopyrimidine-indolines] 64 by multicomponent one-pot reactions of isatins with active methylene compounds, i.e., malononitrile or alkyl 2-cyanoacetates, and 4H-benzothiazolo-pyrimidinone in ethanol/trimethylamine at reux temperature (Scheme 36). The function of the catalytic base is to ease the condensation of isatin with active methylene to generate the individual arylidene intermediates.…”

“…The mechanism of the formation of this class "spirooxoindoles" is complemented with the same sequence of the aforementioned spiro[benzothiazolopyranopyrimidine-indolines]. 132 Safaei-Ghomi et al 134 have developed the use of the CuO/ ZnO@N-GQD nanocomposite for the synthesis of tetrahydrospiro[indoline-3,8 0 -pyranopyrimidines] via one-pot threecomponent reactions. Therefore, isatins reacted with active methylene compounds such as malononitrile, or methyl/ethyl 2cyanoacetate and barbituric acids with 10 mol% of the nanocatalyst in water to give the desired products 66a-t.…”

Recent update on synthesis of spiro-heterocycles in alcohol using malononitrile as a building block

“…A catalytic amount of triethyl amine was also found effective for the synthesis of 2-amino-2',5-dioxo-5H-spiro[benzo [4,5]thiazolo [3,2-a]pyrano [2,3-d]pyrimidine-4,3'-indoline]−3-carbonitrile derivatives 50. 46 Here, Miri et al, in this methodology involved malononitrile/active methylene compound, isatins and 2-Hydroxy-4Hbenzo [4,5]thiazolo [3,2-a]pyrimidin-4-ones 49 in one-pot (Scheme 21). The reaction proceeded in ethanol medium at 70 o C. The merits of this protocol are easy operation, benign towards environment and excellent yields.…”