Synthesis and characterization of derived imines from 4-imino-5,6,7,8- tetrahydro-1-benzothieno[2,3-d]pyrimidin-3(4H)-amine

The synthesis and characterization of derived imines from 4-imino-5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidin-3(4H)-amine 3 have been developed in three steps through the reaction of heteroaromatic o-aminonitrile 1 with triethyl orthoformate. The process afforded the corresponding of imido ester 2 and was followed by cyclization with hydrazine hydrate to furnish iminothienopyrimidineamine 3 and, finally, the imination of 3 with aromatic aldehydes generated the corresponding imines (5a-5h). It is worth mentioning that the process was done at room temperature. The new products were obtained in high yield with an easy work-up in simple reaction along with the purification of products by non-chromatographic method. This general synthetic procedure which can be extended to the preparation of wide variety of imines using o-aminonitrile bifunctional derivatives can also be synthesized by Gewald reaction.