Polymethinfarbstoffe, III. Mitteil.) Über vinylen‐homologe Aldehyde der Pyrrolreihe

Abstract

Nr. 7119541 Strell. Rreis: Polumethinfarbstoffe 1III.I 101 1 169. Mart in S t r ell und Fritz Kr eis: Polymethinfarlbstoff e, III. Mitteil.") : tfber vinylen-homologe Aldehyde der Pyrrolreihe Es wird eine Methode zur Darstellung der ersten Glieder von vinylenhomologen F'yrrolaldehyden beschrieben. Diem Verbindungen wurden u. a. chmakterisiert durch ihre 2.4-Dinitro-phenylhydrazone. AuSerdem komten mit Hilfe dieser Aldehyde neue unsymmetrische Polymethinfarbstoffe hgestellt werden. *) II. Mitteil.: M. Strell, W. B. B r e u n b r u c k u. L. R e i t h m a y r , Liebigs -4nn.

4-Thiazolidinones.

“…The reaction was first performed with rhodanine and benzaldehyde or acetaldehyde, using sulfuric acid as the condensing agent (462), and the isolation of a product was believed to support an open-chain formula for rhodanine, HSCH2COSCN. Later, sodium hydroxide in ethanolic solution (683), sodium ethoxide in ethanolic solution (666), anhydrous sodium acetate in acetic acid (36,345), anhydrous sodium acetate, acetic anhydride, and acetic acid (386), ammonia and ammonium chloride in ethanolic solution (11,96,268), ammonium hydroxide in ethanolic solution (143), diethanolamine (332), and piperidine (490,571) were used as condensing agents. Sometimes the reaction proceeds eo rapidly that the refluxing solution without an additional condensing agent is sufficient (37,486).…”

Electrophilic Substitution of the Pyrrole Ring

“…(297) The reaction of pyrroles with aromatic aldehydes can take several courses depending upon the reaction conditions. (297) The reaction of pyrroles with aromatic aldehydes can take several courses depending upon the reaction conditions.…”

Recent Advances in the Chemistry of Pyrrole.

“…It was shown that 2-dichloromethyl-3,5-dicarbethoxy-4-methylpyrrole reacts with glacial acetic acid to form pyrrylaldehyde and acetyl chloride (108). Several vinylogs of pyrrole aldehydes were prepared according to the general scheme (405) Di-( -pyrrole) -1,4-butanediones were prepared according to the following scheme (80).…”