-Acidic Compounds with Orthoamides of Carboxylic Acids and Alkyne Carboxylic Acids

(1)

Orthoamide, LVIII [1].

Kondensationsreaktionen von CH

₂

-aciden Verbindungen mit Orthoamiden von Carbons¨auren und Alkincarbons¨auren

^*

Orthoamides, LVIII [1]. Condensation Reactions of CH

₂

-Acidic Compounds with Orthoamides of Carboxylic Acids and Alkyne Carboxylic Acids

Willi Kantlehner

^a^;^b

, Erwin Haug

^a

, R¨udiger Stieglitz

^b

, Wolfgang Frey

^b

, Ralf Kress

^b

und Jochen Mezger

^b

aFachbereich Chemie / Organische Chemie, Fachhochschule Aalen, Beethovenstr. 1, D-73430 Aalen,

bInstitut f¨ur Organische Chemie, Universit¨at Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart Sonderdruckanforderungen an Prof. Dr. W. Kantlehner. Fax +49(7361)576250.

E-mail: willi.kantlehner@fh-aalen.de

Herrn Prof. Dr. Volker Figala zum 60. Geburtstag gewidmet

Z. Naturforsch.57 b,399–419 (2002); eingegangen am 11. Januar 2002 Carboxylic Orthoacid Amides, Condensation Reactions, Push-pull-butadienes

The orthoamide derivatives 1s and 2e were prepared from the guanidinium salt 7a and the appropriate carbanions. Cleavage of the orthoamide2ewith benzoyl chloride affords the amidinium salt10a, which can be transformed into the amidinium salt10bby an anion exchange reaction. The enamines11a-i,12a-c,13a,b,14a-c,15a,b,16,17a, b,18a,b,19a,b,20were prepared by condensation of CH₂-acidic compounds with the carboxylic acid orthoamides 2a-j. The orthoamide2dreacts with 1-nitropropane to give the amidinium salt27awhich is transformed into the salt27b. From benzyl cyanide and orthoamides 2g,ithe enamines 30 and32were obtained. Similar condensation reactions were performed with the orthoamides of alkyne carboxylic acids1b,1c,1d,1e,1p,1s, giving the push-pull-butadiene derivatives35a-f, 36a-f,37a-j,38a,b,39a,b,40a,b. Crystal structure analyses of the butadiene derivatives37a, 39a,b,40a,band42were performed, showing that in37a,39b,40a,bby far the shortest bond distance is between C-2 and C-3 of the butadiene system. In39athe bonds between C1-C2, C2-C3 and C3-C4 are nearly of equal length, whereas in the 1,3-diene unit of42the shortest bonds are between C1-C2 and C3-C4.