An efficient, three-component synthesis and molecular structure of derivatives of 2-amino-3-R-6-ethyl-4,6-dihydropyrano[3,2-c][2,1]benzothiazine-5,5-dioxide spirocombined with a 2-oxindole nucleus

Updating the CSIC Reaction (2003–2020)

“…[52] In an alternative approach, compounds 144 (or 145) were prepared by CSICr of 1-ethyl-1H-benzo[c][1,2]thiazin-4(3H)-one 2,2-dioxide (95 c) with the corresponding 2-oxoindolinilidenes, synthesized by Knoevenagel type reaction of isatine and malononitrile [or ethyl cyanoacetate]. [52] The molecular structures of compounds 144 (or 145) were unequivocally determined and assigned by their analytical, NMR spectroscopic data, and X-ray diffraction analysis. [52] Finally, Ukrainets and colleagues reported an efficient synthetic method for the preparation of N-(arylalkyl)-4-hydroxy-2,2-dioxo-1H-benzo[c][1,2]thiazine-3-carboxamides based on the amidation of alkyl 4-hydroxy-2,2-dioxo-1H-2λ 6 ,1-benzothiazine-3-carboxylates with arylalkyl-amines in xylene, at reflux, that affords the final products pure and in good chemical yields.…”

“…[52] The molecular structures of compounds 144 (or 145) were unequivocally determined and assigned by their analytical, NMR spectroscopic data, and X-ray diffraction analysis. [52] Finally, Ukrainets and colleagues reported an efficient synthetic method for the preparation of N-(arylalkyl)-4-hydroxy-2,2-dioxo-1H-benzo[c][1,2]thiazine-3-carboxamides based on the amidation of alkyl 4-hydroxy-2,2-dioxo-1H-2λ 6 ,1-benzothiazine-3-carboxylates with arylalkyl-amines in xylene, at reflux, that affords the final products pure and in good chemical yields. [53] This is thus an effective alternative procedure to that reported years ago by Lombardino, [44] who described the synthesis of the same amides by reacting 3,4-dihydro-2,2-dioxo-Scheme 32.…”

“…[35] Entry NH-CSICr precursor The synthesis of diversely substituted 1H-benzo[c][1,2] thiazin-4(3H)-one 2,2-dioxides III (Figure 2) follows a well and simple three-step protocol proposed by Lombardino in the seventies, [44] consisting of the CSICr of a N-alkyl-N-(methylsulfonyl)anthranilate, obtained from the reaction of an anthranilate and methanesulfonyl chloride, followed by Nalkylation of the resulting intermediate. This procedure has been used later by other authors without significant modifications, under conventional conditions [43,[45][46][47][48][49][50][51][52][53][54][55][56] or solid-phase, a very appropriate method for the combinatorial synthesis of heterocyclic compound libraries, albeit in low chemical yields. [57] Scheme 15.…”

The synthesis, anti-inflammatory, analgesic and antimicrobial activities of ethyl 2-amino-4-alkyl-4,6-dihydropyrano[3,2c][2,1]benzothiazin-3-carboxylate 5,5-dioxides and triethylammonium 3-[(4-hydroxy-1-ethyl-2,2-dioxido-1h-2,1-benzothiazin-3-yl)alkyl]-1-

“…The starting 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide was obtained according to the procedure previously described [21] ammonium) 3,3′-[1,5-bis(4-hydroxy-1-ethyl-2,2-dioxido-1H-2,1-benzothiazin-3-yl)pentane-1,5-diyl]bis(1-ethyl-1H-2,1-benzothiazin-4-olat 2,2-dioxide) (7i). To the solution of 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide 1 (0.450 g, 0.002 Mol) and 50% water solution of glutaric aldehyde 3i (0.105 g, 0.0005 Mol) in ethanol (10 mL) add triethylamine (0.101 g, 0.001 Mol).…”

The study of the three-component interaction between 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide, heterylcarbaldehydes and active methylene nitriles

“…We used this property in order to synthesize a new heterocyclic system of 2-amino-3-R-6-ethyl-4,6-dihydropyrano[3,2-c][2,1]benzothiazine 5,5-dioxide spirocondensed with the 2-oxindole core. The target compounds were obtained using the three-component interaction of 1Н-2,1-benzothiazin-4(3Н)-one 2,2-dioxide with isatins and active methylene nitriles [19]. This article was the first one dedicated to the multicomponent reactions of 1Н-2,1-benzothiazin-4(3Н)-one 2,2-dioxide.…”