HELVETICA CHIMICA ACTA ~ Vol. 81 (1998) 231 Synthesis and Transformations of Methyl (E)-2-(Acetylamino)-3- cyanoprop-2-enoate und Methyl (E)-2-(Benzoylamino)-3-cyanoprop-2-enoate, Versatile Reagents for the Preparation of Polyfunctional Heterocyclic Systems by Lucija Pizzioli, Brina Ornik, Jurij Svete, and Branko Stanovnik* FdCUfty of Chemistry and Chemical Technology, University of Ljubljana, ASkerteva 5, POB 537, 1000 Ljubljana, Slovenia Methyl (E)-2-(acetylamino)-3-cyanoprop-2-enoate (2a) and its 2-benzoyl analog 2b were prepared from the corresponding methyl (Z)-2-(acylamino)-3-(dimethylamino)propenoates 1. Multifunctional compounds 2 are versatile synthons for preparation of polysubstituted heterocyclic systems such as pyrroles 4, pyrimidines 5 and 6, pyridazines 7, pyrazoles 8, 9, and 11, and ~sox~zoles 10. Introduction. ~ Derivatives of 2-amino-3-cyanoprop-2-enoates have been prepared from dichloromaleic anhydride [l] and by condensation of alkyl cyanoformates and analogous compounds with active methylene compounds [2-41. Inspite of the fact that these compounds have been described as precursors for the synthesis of a$-didehydro-a- amino acids, reactions involving either CN or ester group have not been reported. Results and Discussion. - In our studies on the syntheses and transformations of alkyl 2-(acylamino)-3-(dimethylamino)prop-2-enoates as simple and versatile reagents for the preparation of various cyclic systems [5][6], we observed that the Me,N group in methyl (Z)-2-(acetylamino)-3-(dimethylamino)prop-2-enoate (la) and methyl (Z)-2-(benzoyl- amino)-3-(dimethyamino)prop-2-enoate (lb), obtained from N-acetylglycine [6] and N-benzoylglycine (hippuric acid) [7] [8], respectively, can be easily exchanged by a CN group to give methyl (E)-2-(acetyIamino)-3-cyanoprop-2-enoate (2a) and methyl (E)-2-(benzoylamino)-3-cyanoprop-2-enoate (2b) in 70 and 52 % yield, respectively (Scheme 1). The configuration around the C=C bond in compounds 2 was established by X-ray analysis l). Since the compounds 2 are multifunctional, they turned out to be useful synthons for the preparation of several polyfunctional substituted five- and six-membered heterocyclic Scheme f NcHcoo& KCN H ’ - H NHCOR ””#” H COOMe HC O la R=Me lb R=Ph 2a R=Me 2b R=Ph I) X-Ray data of structure analyses of the compounds 2a and 2b will be published elsewhere