- Enaminones in organic synthesis: A novel synthesis of 1,3,5-trisubstituted benzene derivatives and of 2-substituted-5-aroylpyridines
-
Enaminones undergo self-condensation on reflux in acidic media yielding 1,3,5-trisubstituted benzene in very high yields. Reaction of enaminones 1a,b with ethyl propiolate affords 5-aroyl-1,3-benzene dicarboxylate derivatives.
- Abdel-Khalik, Mervat Mohammed,Elnagdi, Mohamed Hilmy
-
-
Read Online
- Regioselectivity in the Reaction of 2-Aminobenzothiazoles and 2-Aminobenzimidazoles with Enaminonitriles and Enaminones: Synthesis of Functionally Substituted Pyrimido[2,1-b][1,3]benzothiazole and Pyrimido[1,2-a]benzimidazole Derivatives
-
A variety of new polyfunctionally substituted benzo[d]pyrimido[2,1-b][1,3]thiazole and benzo[4,5]imidazo[1,2-a]pyrimidine derivatives have been synthesized. The general synthetic procedure used for this purpose involves the condensation of 2-aminobenzothiazole and 2-aminobenzimidazole with a variety of enaminonitriles, enaminones, and acrylaldehyde. The regioselectivity for initial attack of either endocyclic ring nitrogen or exocyclic amino group was studied and rationalized for. It has been concluded that ring nitrogen is the most reactive cite in acidic medium, and cyclic intermediate can also be isolated, attesting to this conclusion upon cyclization. However, in basic or neutral medium, the exocyclic amino group was found to be the most reactive center. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible.
- Alnajjar, Abdulaziz,Abdelkhalik, Mervat Mohammed,Riad, Hossam Mohammed,Sayed, Samia Mohammed,Sadek, Kamal Usef
-
p. 2760 - 2765
(2018/11/10)
-
- Studies with Enaminones: The reaction of enaminones with Aminoheterocycles. A route to Azolopyrimidines, Azolopyridines and Quinolines
-
The enaminones 1b,d,f react with 4-phenyl-3-methyl-5-pyrazoleamine 3a to yield the pyrazole derivatives 4a-c that cyclised readily on reflux in pyridine solution in presence of hydrochloric acid to yield the pyrazolo[1,5-a]pyrimidines 5a-c. Similarly 3(5)
- Almazroa, Sarah,Elnagdi, Mohamed H.,Salah El-Din, Abdellatif M.
-
p. 267 - 272
(2007/10/03)
-
- Synthesis and Stereoselective Reduction of C-7 Oxygenated Quinolizinium Salts
-
The title compounds have been prepared by Hantzsch condensation of protected 5-hydroxy-2-pyridylacetates with enol ethers of furoylacetaldehydes.The reduction with sodium cyanoborohydride yielded a mixture of corresponding trans-fused quinolizidines and Δ
- Golebiewski, W. Marek,Wrobel, Jerzy T.
-
-