Synthese von Pyridin‐Derivaten aus Dichlor‐äther und β‐Amino‐crotonsäureester

Abstract

Dichlor-ather und B-Amino-arotoneBureeater. [Aus dem Chemischen Institut der Universit&t Berlin.] (Eingegangen am 14. Febrnar 1911.) Lost man 6-Amino-crotonsiiureester in der gleichen Menge 1.2-Dichlor-iither, LO erfolgt nach kurzem Stehen heftige Reaktion. Als Produkt der Urnsetzung 1iiBt sich eine krystallinische Chlorververbindung isolieren , der die ernpirische Formel CMH~OOIN GI zukommt. Die Bildung der Substanz kann durch folgende Gleichung veranschaulicht werden : CH~CI.CHCl(OCtH;) + 2CH3.C(NHo) : CH.CO.OCs& = CIdHsoOpNCI + CsHs.0H + NHrCI.

Diversified Synthesis of Furans by Coupling between Enols/1,3‐Dicarbonyl Compounds and Nitroolefins: Direct Access to Dioxa[5]helicenes

“…Owing to their broad range of activities, several methods have been developed for the synthesis of furan derivatives. The important classical approaches are the Paal–Knorr, and Feist–Benary syntheses,, which have been established for the assembly of polysubstituted furans from dicarbonyl compounds. Prefunctionalized acyclic ketone derivatives, such as α‐aryloxyketones, o ‐alkoxyketones,, cyclopropenyl ketones, allenyl ketones, and β‐acyloxy acetylenic ketones, have also been employed as key starting materials for the construction of this scaffold.…”

The Synthesis of the Pyrrole Ring

“…(46,47) However, it has been found that the relative yields of pyrroles and furans produced by Benary's procedure (Table 3.2) depend upon the choice of amine. (45,)) It has been found that whereas an increase in the size of the groups R 1 , R 3 , and R 4 is detrimental to the formation of the pyrrole, large R 2 groups apparently aid the reaction.…”

Synthesis of Nitrogen-containing Heterocyclic Compounds by Ring Enlargement Reactions through Bicyclic Cyclopropane Intermediates (Review)

“…Thus, at room temperature in ethanol solution 4-ethoxy-4,5-dihydro-1H-azepines 14 and 15 were obtained in high yields. These compounds were relatively unstable and in solution readily lost ethanol with the formation of 4H-azepines 16 The 4H-azepines 16 and 17 were also formed directly from the dihydropyridines 1 and 4 during reaction with EtONa in refluxing diethyl ether or with potassium cyanate in refluxing ethanol (yields 79-92%). Treatment of the pyridine 1 or 4H-azepine 16 with sodium ethoxide in refluxing ethanol led to formation of the 3H-azepine 18.…”

“…Synthesis of these compounds was described in a series of publications by the German chemist Benary about 100 years ago [16][17][18][19]. Benary studied the reactions of some of the obtained compounds with nucleophilic reagents and showed in particular that the reactions with KSH and KCN resulted in the formation of products from nucleophilic substitution of the halogen atom, to which he assigned the structures of the corresponding 4-(mercaptomethyl)-and 4-(cyanomethyl)-substituted 1,4-dihydropyridines [17][18][19].…”