Quinazoline derivatives and their pharmaceutically acceptable acid addition salts having the general formula ##STR1## wherein R.sup.1 and R.sup.2 each represents hydrogen or alkyl; R.sup.3 represents alkyl or substituted alkyl; R.sup.7 and R.sup.8 each represent alkoxy; Z is oxygen or sulfur; m is zero or 1; n is zero or an integer from 1 to 5, exhibit a cardiotonic activity with little tendency to cause tachycardia.
A new method for peptide synthesis in the N→C direction: amide assembly through silver-promoted reaction of thioamides
作者:Aysa Pourvali、James R. Cochrane、Craig A. Hutton
DOI:10.1039/c4cc07601j
日期:——
The Ag(I)-promoted coupling of amino acids and peptides with amino ester thioamides generates peptide imides without epimerisation. The peptide imides undergo regioselective hydrolysis under mild conditions to generate native peptides. This method was employed to prepare the pentapeptide thymopentin in the N-->C direction, in high yield and purity.