An eco-compatible synthesis of medicinally important novel class of trispiroheterocyclic framework using 2,2,2-trifluoroethanol as a reusable medium

Azomethine Ylides—Versatile Synthons for Pyrrolidinyl-Heterocyclic Compounds

“…Trispiropyrrolidines/thiapyrrolizidines 163 and 164 were synthesized through the reaction of 7,9-bis[( E )-ylidene]-1,4-dioxa-spiro[4,5]decane-8-ones 162 and azomethine ylides (formed from isatin 19 and sarcosine 20 or thioproline 22 ) in 2,2,2-trifluoroethanol (TFE) ( Scheme 54 ). Some of the products showed anti-fungal properties (against Candida albicans MTCC 227, Aspergillus niger MTCC 282, and Aspergillus clavatus MTCC 1323) and antimycobacterial properties against M. tuberculosis H37Rv relative to the standard references Nysyatin, Greseofulvin (antifungal), and Isoniazid (antimycobacterial) [ 82 ].…”

An eco-compatible synthesis of novel spiro[acenaphthylene-1,2′[1,3]-thiazolidine]-2,4′(1H)-diones using thiamine hydrochloride as efficient catalyst in aqueous medium

“…Hence, inspired by these findings and in continuation of our ongoing work to develop environmentally benign methodologies [54][55][56][57][58][59][60][61] for the synthesis of biologically useful heterocycles, we have investigated a threecomponent protocol for the synthesis of drug-like spiro[acenaphthylene-1,2 0 [1,3]-thiazolidine]-2,4 0 (1H)-diones from the multi-component reaction of acenapthaquinone, substituted anilines, and a-mercaptoacetic acid in good yield using thiamine hydrochloride as a green, inexpensive, and reusable catalyst in aqueous medium. The present method is more convenient and efficient because it obviates the azeotropical removal of water and use of carcinogenic solvents as well as dehydrating agents.…”

Microwave‐Assisted Synthesis of Fluorinated 5‐Membered Nitrogen Heterocycles

“…Medicinally important, fluorinated trispiropyrrolidine/ thiapyrrolizidine derivatives were synthesized in a two-step synthetic process employing 2,2,2-trifluoroethanol (TFE) as a reusable solvent. [62] In the first step, 7,9-bis[(E)arylidene]-1,4-dioxaspiro [4,5]decane-8-ones ( 16) was synthesized by treatment of spiro [4,5]decan-8-one (15) with 4-fluorobenzaldehyde and potassium carbonate (K 2 CO 3 ) in water under MW heating in excellent yield in short reaction time as compared to conventional heating (Scheme 7). [63] The compound 16 obtained in this step was further reacted with isatin and sarcosine or thiaproline in TFE to get the fluorinated trispiropyrrolidine (17) or pyrrolothiazole (18) derivatives respectively (Scheme 7).…”