Interaction of indolylzinc chloride with 2-chloro-3-nitrothiophene gave 3-(3nitrothien-2-yl)indole (7) which was converted, via reduction followed by acylation, into 3-(3-acylaminothien-2-yl)indoles (9a-c). Cyclization of 9a-c induced by phosphorus oxychloride under Bischler-Napieralski reaction conditions, took place regioselectively at the indolic C-4 locus to furnish the respective thieno[2',3' : 6,7]azepino[5,4,3-cd]indoles (3a-c). INTRODUCTION Various types of azepine-fused heterocycles, such as thienoazepines 1 and azepinoindoles, 2 have been investigated. Amongst, few recent reports dealt with the synthesis and medicinal activities of compounds having the thieno[3,2-b]azepine skeleton (1), 3-5 bioisostere of benzo[b]azepine. Some derivatives of the latter system are known to display activities such as anticancerigen, 6 calcium antagonists 7 and central nervous system depressors. 8 Different thieno[3,2-b]azepines showed vasopressin V1, V2 and oxytocine antagonist activity, 4 as well as affinity towards dopamine D2, serotonin 2 and serotonin 1A receptors. 5 More recently, series of synthetic tricyclic heterocycles structurally based on the thieno[3,2-b]azepine skeleton, have revealed interesting biological activity. Examples include substituted pyrazolo[3,4-d] thieno[3,2-b]azepines, acting as potent orally active arginine vasopressin (AVP) receptor antagonist, 9 and pyrido[3,2-d]thieno[3,2-b]azepine derivatives, exhibiting a remarkable selectivity for renal tumor cell lines. 10 On the other hand, the azepino[5,4,3-cd]indole system constitutes the skeleton of the ergot alkaloid claviciptic acid (2). 11 Some synthetic analogs of 2 were reported to exhibit potent activity on the central nervous system with potential against migraine attacks, 12 while others were described as dopamine D-1