The thiophene derivative 1 reacts with the active methylene reagents 2a-c to afford the thieno[2,3-d]pyrimidine derivatives 6a,b and 8, respectively. 1 reacts with phenacyl bromide 2d to afford the N-alkylation product 9 and reacts with phenacyl thiocyanate 2e to afford the N-(thiazol-2-yl) derivative 10, which was further cyclized into thiazolo[3,2-a]thieno[2,3-d]pyrimidine derivative 12. Compound 1 reacts also with the cinnamonitriles 3a,b to afford the thieno[2,3-b]pyridines 15a,b, respectively. 1 undergoes either acetylation or hydrolysis to afford the thieno[2,3-b]pyridine derivative 19 and the thiophene derivative 22, respectively. Some of the new compounds show inhibitory effect to the production of mycotoxins and to fungal growth.