54968-59-1

Upstream product

• 105-39-5 chloroacetic acid ethyl ester 
• 38201-60-4 2-mercapto-6,7,8,9-tetrahydro-3H-benzo[4,5]thieno[2,3-d]pyrimidin-4-one 
• 60442-41-3 2-chloroacetylamino-3-carbethoxy-4,5,6,7-tetrahydrobenzothiophene 
• 333-20-0 potassium thioacyanate 
• 105544-62-5 N-(3-carboethoxy-4,5,6,7-tetrahydrobenzo[b]thien-2-yl)-N-thiourea 
• 4506-71-2 ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate 
• 64-17-5 ethanol 
• 38201-60-4 4-oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydrobenzothieno<2,3-d>pyrimidine 

Relevant academic research and scientific papers

Studies on synthesis and reactions of some new five and six-membered heterocycles bearing 5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-ones skeleton

Thienopyrimidine derivatives are well-known in various pharmaceutical and biomedical domains. In this work, a series of efficacious and novel strategies for the synthesis of thienopyrimidines starting from 2-amino-3-carboethoxy-4,5,6,7-tetrahydrobenzo[b]thiophene has been developed. The regioselectivity of these synthetic strategies was investigated using density functional theory computation and spectroscopic analysis. In addition, the chemical structures of the new thienopyrimidines and their reaction mechanisms, as well as the biological activity of selected compounds were studied.

New syntheses of 2-alkylthio-4-oxo-3,4-dihydroquinazolines, 2-alkylthioquinazolines, as well as their hetero analogues

N-Chloroacetylanthranilic acid ethyl ester reacts with potassium thiocyanate in the presence of alcohol to give the (4-oxo-3,4-dihydroquinazolin-2-ylsulfanyl)acetic acid ester (3a). In the presence of water or amines the acetic acid derivative (3b) or the acetamide derivatives (3c,d) are obtained. 2-Amino-4-oxo-3,4-dihydroquinazolines (4) arise if vigorous reaction conditions are employed. Analogously, N-chloroacetyl derivatives of 5-membered heterocycles with enaminocarbonyl structure (5, 7, 9, 11, 13, 20, 23) react with potassium thiocyanate to yield thieno[2,3-d]-, thieno[3,2-d]-, imidazo[4,5-d]-, pyrrolo[3,2-d]-, and thiazolo[4,5-d]pyrimidines (6, 8, 10, 12, 14, 21, 24). Quinazolines (18, 19) are formed from the reaction of 2-chloroacetylaminoacetophenone (16a) and 2-chloroacetylaminobenzophenone (16b) with potassium thiocyanate and subsequent treatment of the intermediates with amines.