Studien zur Chemie von thienoanellierten O,N‐ und S,N‐haltigen Heterocyclen, 8. Synthese eines racemischen, thienoanalogen Diltiazems mit potentieller Calciumkanal blockierender Wirkung

Studies on the Chemistry of Thieno‐Annulated O,N‐ and S,N‐Containing Heterocycles, 8 [1]. –Synthesis of a Racemic, Thieno Analogue Diltiazem with Potential Ca 2+ Antagonistic Activity The synthesis of the thieno analogue diltiazem cis ‐8‐[2‐(di‐methylamino)ethyl]‐5,6,7,8‐tetrahydro‐5‐(4‐methoxyphenyl)‐7‐oxothieno[3,2‐ b ][1,4]thiazepin‐6‐yl acetate ( 1 ) is described. Reaction of 3‐bromo‐2‐nitrothiophene with Na 2 S · 9H 2 O yields the intermediate 3‐mercapto‐2‐nitrothiophene ( 6 ), which reacts with the racemic glycidate 7 to give the racemic threo compound 10. Reduction and cyclization of 10 furnish the thieno [3,2‐ b ][1,4]thiazepine derivative 12. N ‐Alkylation and acetylation of the hydroxy group of 12 leads to 1 .