The regiochemistry of 1. 3-dipolar cycloaddition reactions of E-3-(dimethylamino)-1-(10H-phenothiazin-2-yl) prop-2-en-1-one with some nitrilimines were investigated using density functional theory (DFT) -based reactivity indexes. activation energy calculations and the distortion/interaction model at B3LYP/6-311G(d. p) level of theory. https://tonerparts.shop/product-category/printheads/