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Showing papers in "Mathematical Problems in Engineering in 1992"

Journal Article•
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 8 [1]. [1]benzothieno[2,3-c]naphtho[1,2-h]quinoline and [1]benzothieno[2,3-c]naphtho[1,2-h][1,2,4]triazolo[4,3-a]quinoline

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Kenji Sasaki1, Raymond N. Castle1•
University of South Florida1
01 Oct 1992-Mathematical Problems in Engineering

1 citations

Journal Article•
Synthesis of quinazolino-1,3-benzothiazine derivatives

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János Szabó1, E. Bani‐Akoto1, György Dombi1, Gábor Bernáth1, Lajos Fodor, Pál Sohár2 •
University of Szeged1, Eötvös Loránd University2
01 Oct 1992-Mathematical Problems in Engineering
TL;DR: The ring-closure reactions of N-(3,4-dimethoxyphenylthio-methyl)-2-nitrobenzamide derivatives 5a,b with phosphoryl chloride gave 4-(2'-nitrophenyl)-2H-1,3-benzothiazine derivatives 7a, b, which on reduction yielded 4-( 2'-aminophenyl)-3, 4-dihydro-2H,1, 3-benZoth
Abstract: The ring-closure reactions of N-(3,4-dimethoxyphenylthio-methyl)-2-nitrobenzamide derivatives 5a,b with phosphoryl chloride gave 4-(2'-nitrophenyl)-2H-1,3-benzothiazine derivatives 7a,b, which on reduction yielded 4-(2'-aminophenyl)-3,4-dihydro-2H-1,3-benzothiazines 8a,b. Reaction of these compounds with phosgene led to the derivatives 9a,b of a new heterocyclic ring system, 6H,8H-quinazolino[3,4-c] [1,3]benzothiazine. The structures of the title compounds were proved by their ir and nmr (1H, 13C) spectra.