Summary
(±)-4-Thiacarnegin (3) was synthesized by reaction of 6,7-dimethoxy-3-methyl-2H-1,3-benzothiazinium iodide (2) with methyl magnesium iodide, thereby opening a new synthetic route to 4-substituted dihydro-2H-1,3-benzothiazines. Compound3 was also obtained by reduction of 6,7-dimethoxy-3,4-dimethyl-2H-1,3-benzothiazinium iodide (5). In a similar way, reduction of the quaternary salts9 a–c afforded the (±)-4-thia analogues of cryptostilin-I, -II and -III (10 a–c). The isomers of the former compounds (12 a–c) were also synthesized by reduction of the 4H-1,3-benzothiazinium salts11 a–c.
Zusammenfassung
Aus 6,7-Dimethoxy-3-methyl-2H-1,3-benzothiaziniumjodid (2) wurde mit Methylmagnesiumjodid (±)-Thiacarnegin (3) dargestellt. Diese Reaktion bietet ein neues Verfahren für die Synthese von 4-substituierten Dihydro-2H-1,3-benzothiazinen.3 wurde auch durch Reduktion von 6,7-Dimethoxy-3,4-dimethyl-2H-1,3-benzothiaziniumjodid (5) erhalten. Die Reduktion der quartären Ammoniumsalze9 a–c ergab ebenfalls die Cryptostillin I-, II-, III-(±)-4-thiaanalogen Verbindungen (10 a–c). Reduktion der 4H-1,3-Benzothiazinium-Salze11 a–c lieferte die entsprechenden Isomeren12 a–c der obengenannten Verbindungen.
Similar content being viewed by others
References
This paper is regarded as Part 149 of the series Saturated Heterocycles. Part 148: Fülöp F., Lázár L., Pelczer I., Bernáth G. (1988) Tetrahedron44: 2993
Szabó J., Fodor L., Varga I., Vinkler E., Sohár P. (1977) Acta Chim. Acad. Sci. Hung.92: 317
Leander K., Luning B. (1968) Tetrahedron Lett.: 1393
Leander K., Luning B., Runsa E. (1969) Acta Chem. Scand.23: 244
Vinkler E., Szabó J. (1955) Acta Chim. Acad. Sci. Hung.6: 323
Szabó J., Fodor L., Varga I., Vinkler E. (1977) Acta Chim. Acad. Sci. Hung.93: 403
Szabó J., Fodor L., Szűcs E., Bernáth G., Sohár P. (1984) Pharmazie39: 426
Kálmán A., Argay Gy., Sohár P., Szabó J., Fodor L., Bernáth G. (1986) J. Mol. Struct.145: 341
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Szabó, J., Katócs, Á., Bernáth, G. et al. Synthesis of 4-thia analogues of isoquinoline alkaloids. Monatsh Chem 120, 463–471 (1989). https://doi.org/10.1007/BF00811558
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00811558