Studies on Heteropentales. IV : Heteroannelations to Pyrrolo[2,1-b]benzothiazole and Pyrrolo[2,1-b]thiazoles

Studies on Heteropentales. IV : Heteroannelations to Pyrrolo[2,1-b]benzothiazole and Pyrrolo[2,1-b]thiazoles

Creators Abe Noritaka

Creators Nishiwaki Tarozaemon

Creators Omori Toshimasa

Creators Harada Emiko

2,3-Dibenzoylpyrrolo[2,1-b]benzothiazole (2) and 6,7-dibenzoylpyrrolo[2,1-b]thiazoles (5a-b) have been synthesized by utilizing the cycloaddition reactions of imidazo[2,1-b]benzothiazole and imidazo[2,1-b]thiazoles, respectively, with dibenzoylacetylene followed by the elimination of a nitrile from each of the cycloadducts. Heteroannelations to 2 and 5 have been achieved by their reactions with hydrazine, aminoacetonitrile, ethyl glycinate, and phosphorus pentasulfide. The annelations by the second and third reagents proceed fairly regioselectively. Facile dimerizations of thieno[3',4':3,4]pyrrolo[2,1-b]benzothiazole and thieno[3',4':3,4]pyrrolo[2,1-b]thiazoles to be produced by the reactions with the last reagent are also described.

[ISSN]0009-2673

[NCID]AA00580132

https://doi.org/10.1246/bcsj.55.200

[isVersionOf] [URI]http://www.jstage.jst.go.jp/browse/bcsj/-char/en