453511-36-9Relevant academic research and scientific papers
Synthesis and Screening of Phosphodiesterase 5 Inhibitory Activity of Fused and Isolated Triazoles Based on Thieno[2,3-d]pyrimidines
Ameen, Mohamed A.,Ahmed, Essam Kh.,Mahmoud, Hemdan I.,Ramadan, Mohamed
, p. 1831 - 1838 (2019)
Novel fused and isolated triazoles based on thieno[2,3-d]pyrimidines were synthesized starting from 2-aminothiophene ester and structurally confirmed by spectral and analytical data. The synthesized triazolo compounds were screened for their phosphodieste
Synthesis of 3-substituted pyrido[4′,3′: 4,5]thieno[2,3-d]pyrimidines and related fused thiazolo derivatives
Ahmed, Essam Kh.
, p. 667 - 679 (2003)
New ethyl 3-(substituted)-4-oxo-2-thioxo-1,2,3,4,5,6,7,8- octahydropyrido[4′,3′:4,5]thieno-[2,3-d]pyrimidine-7- carboxylates (3a,b), (6), (11-13), ethyl 3-methyl-5-oxo-2,3,6,9-tetrahydro 5H-pyrido[4′,3′:4,5]-thieno[2,3-d][1,3]thiazolo[3,2-a] pyrimidine-8(7H)-carboxylate (4), and ethyl 2-methyl-5-oxo-2,3,6,9-tetrahydro-5H-pyrido[4′,3′:4,5]thieno- [2,3-d][1,3]thiazolo[3,2-a]-pyrimidine-8(7H)-carboxylate (8) have been synthesized from diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno-[2,3-c]pyridine-3,6-dicarboxylate 1. The structure of these compounds as well as their intermediates have been established by their spectral data.
Synthesis of 3-substituted pyrido [4′,3′:4,5]-thieno[2,3-d]pyrimidines and related fused thiazolo derivatives
Ahmed, Essam Kh.
, p. 201 - 207 (2003)
The synthesis of 3-substituted pyrido [4′,3′:4,5]-thieno [2,3-d] pyrimidines and related fused thiazolo derivative was discussed. The absorption band due to NH, ester CO and pyrimidine ring CO was elaborated. The reaction of diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothienol[2,3-c] pyridine-3,6-dicarboxylate with amino acids glycine, L-alanine and β-alanine in a mixture of dioxane and water under mild conditions was investigated for the synthesis of pyridothienopyrimidine derivatives.
A novel synthetic routes to new 3-substituted-4-oxo-3,4,5,6,7,8- hexahydropyridol[4′,3′,4,5]-thieno[2,3-d]pyrimidine-7-carboxylic acid ethyl ester derivatives
Ahmed,Abdel-latif,Ameen
, p. 95 - 107 (2007/10/03)
Orthoaminoester 1 was investigated by the reaction with ethylchloroformate, 5-phenyl-oxadiazol-2-thione and triethylorthoformate to afford the open structures, 2, 13 and 15. These compounds were subjected to ensuing cyclization in one step or more yielding 3-substituted-5,6-dihydro-8H-4-oxopyrido[4′, 3′,4,5]thieno[2,3-d]pyrimidine-7(6H)-carboxylic acid ethyl ester derivatives. Copyright Taylor & Francis Inc.
A convenient synthesis for some new pyrido [4′,3′:4,5]thieno[2,3-d]pyrimidines and related fused 1,2,4-triazolo and 1,3,4-thiadiazolo-derivatives
Ahmed, Essam Kh.
, p. 1323 - 1336 (2007/10/03)
Diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate 1 is a convenient and useful starting matrial for the constructions of heterocyclic systems. It was utilized to synthesize derivatives of the novel heterocyclic systems pyrido[4′,3′:4,5]thieno-[2,3-d]pyrimidine 4,10, pyrido[4′,3′:4,5]thieno[2,3-d]-[1,2,4]triazolo-[1,5-a]pyrimidine 7,11a-e and pyrido[4′,3′:4,5]thieno[2,3-d][1,3,4]-thiadiazolo[3,2- a]pyrimidine 12-14.
Syntheses of some new azolopyrido-[4′,3′:4,5]thieno[2,3-d]pyrimidines
Ahmed, Essam Kh.
, p. 280 - 286 (2007/10/03)
Diethyl2-[(ethoxythioxomethyl)amino]4,5,6,7-tetrahydrothieno[2,3-c]-pyridin e-3,6-dicarboxylate 2, prepared from diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate 1 by boiling in anhydrous ethanol, was converted into pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidine derivatives 3, 4 by treatment with hydrazine hydrate. The tetracyclic systems imidazo[1,2-a]pyrido-[4′,3′:4,5]-thieno[2,3-d]pyrimidine 9 and pyrido[4′,3′:4,5]-thieno[2,3-d][1,3]thiazolo-[3,2-a]pyrimidine 10 were synthesized by the reaction of 2 with 1,2-diaminoethane and aminoethanethiol, respectively. The hydrazino derivative 4 underwent cyclization reactions with orthoesters and nitrous acid to give the corresponding pyrido[4′,3′:4,5]thieno[2,3-d][1,2,4]triazolo[1,5-a]pyrimidines 5, 6 and pyrido[4′,3′:4,5]thieno[3,2-e][1,2,3,4]tetrazolo[1,5-a]pyrimidine 8, respectively. Moreover, reactions of 3 with cyanogen bromide, N-carbethoxyhydrazine, carbon disulfide, and ethyl chloroformate resulted in the formation of the new pyrido[4′,3′:4,5]thieno[2,3-d][1,3,4]thiadiazolo-[3,2-a]pyrimidine derivatives 12-15.
Synthesis of new pyrido[4″,3″:4′,5′]thieno[2′,3′:4, 5]pyrimido-[2,1-b][1,3,4]thiadiazine derivatives
Ahmed, Essam Kh.
, p. 989 - 1000 (2007/10/03)
Ethyl 2-methyl-11-oxo-9, 10-dihydro-1H, 11H-pyrido[4″,3″:4′,5′]thieno-[2′,3′:4, 5]pyrimido[2,1-b][1,3,4]thiadiazine-8(7H)-carboxylate 7 has been synthesised by the reaction of ethyl 3-amino-4-oxo-2-thioxo-1,3,4,5,6,8-hexahydropyrido[4′,3′:4,5] thieno[2,3-
