Reactions of (E)-N-methyl-3-(6,11-dihydrodibenzo[b,e]thiepin-11-ylidene)propylamine (V) with phenacyl chloride and 4-chlorophenacyl bromide in chloroform in the presence of sodium or potassium carbonate afforded the title compounds VI and VII. Their hydrochlorides showed very low acute toxicity in mice but in comparison with prothiadene (IV), they were less effective in the common animal tests used for assessing the thymoleptic activity (inhibition of reserpine-induced hypothermia and ptosis in mice, potentiation of yohimbine toxicity in mice, anticataleptic action in rats). These activity relations are in disagreement with those published for the analogous pair of 10,11-dihydrodibenz[b,f]azepine derivatives imipramine (I) and lofepramine (III).