Synthesis of new oxindole derivatives containing benzothiazole and thiazolidinone moieties using nano silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (NSB-DBU) as catalyst

Abstract

A facile one-pot synthesis of novel oxindole derivatives bearing benzothiazolylmethyl-2-thioxothiazolidin-4one was accomplished via one-pot reaction of 5-oxoindolinylidene rhodanine-3-acetic acid derivatives, 2-aminothiophenol, and triphenyl phosphite in the presence of tetrabutylammonium bromide (TBAB) and nano silica-bonded 5-n-propyloctahydro-pyrimido[1,2-a]azepinium chloride (NSB-DBU) as heterogeneous reusable nanocatalyst. The target compounds were obtained in excellent yields (85%-92%) and short reaction times under fairly mild reaction conditions.

Solid‐Supported Materials‐Based Synthesis of 2‐Substituted Benzothiazoles: Recent Developments and Sanguine Future

“…NSB-DBU mediated synthesis of 2-substituted benzothiazoles. [220] 80°C for 20 min (Scheme 39). The developed protocol tolerated well electronically diverse aldehydes as substrates.…”

“…Baharfar & Shariati [220] developed 5‐ n ‐propyloctahydro‐pyrimido[1,2‐ a ]azepinium chloride (NSB‐DBU) as a heterogeneous reusable catalyst for the synthesis of oxindole analogs having thiazolidinone and benzothiazole moieties in a single matrix. The reaction was investigated initially with different molar ratios of NSB‐DBU and TBAB (tetra‐ n ‐butylammonium bromide) at different temperatures by varying the duration of the reaction.…”

Recent advances on the nanocatalyzed synthesis of 1,3‐thiazolidines

“…As the proposed mechanism, first, rhodanine- and nano silica-bonded 5-n-propyloctahydro-pyrimido [1,2-a]azepinium chloride (NSB-DBU) (Scheme 54). [47] The catalyst is reusable for nine times.…”

Copper/Schiff‐base complex immobilized on amine functionalized silica mesoporous magnetic nanoparticles under solvent‐free condition: A facile and new avenue for the synthesis of thiazolidin‐4‐ones

“…[44][45][46] The newest methodology is synthesis of bis-thiazolidinones through multicomponent reaction of aldehydes, ethylenediamine, and thioglycolic acid using (a) nano-CdZr 4 (PO 4 ) 6 [47] and (b) chitosan-attached nano-CuFe 2 O 4 , [48] and synthesis of oxindole derivatives containing thiazolidinone using nano silica-bonded 5-n-propyl-octahydro-pyrimido [1,2-a] azepiniumchloride via a one-pot reaction of 5-oxoindolinylidene rhodanine-3-acetic acid derivatives, 2-aminothiophenol, and triphenyl phosphite. [49] Mesoporous silicas are inorganic materials formed by the condensation of sodium silicate or silicon alkoxides around an ordered surfactant used as template. The synthesis of these porous silicas, as well as their porous structure, depends on several parameters, such as the silicon source, the morphology of the surfactant, pH conditions, ionic strength, aging temperature, aging time, and so on.…”

“…[ 44–46 ] The newest methodology is synthesis of bis‐thiazolidinones through multicomponent reaction of aldehydes, ethylenediamine, and thioglycolic acid using (a) nano‐CdZr 4 (PO 4 ) 6 [ 47 ] and (b) chitosan‐attached nano‐CuFe 2 O 4 , [48 ] and synthesis of oxindole derivatives containing thiazolidinone using nano silica‐bonded 5‐ n ‐propyl‐octahydro‐pyrimido[1,2‐a]azepiniumchloride via a one‐pot reaction of 5‐oxoindolinylidene rhodanine‐3‐acetic acid derivatives, 2‐aminothiophenol, and triphenyl phosphite. [ 49 ]…”