Crystal structure of diethyl 2-amino-5-{4-[bis­(4-methyl­phen­yl)amino]­benzamido}­thio­phene-3,4-di­carboxyl­ate

In the title compound, C(31)H(31)N(3)O(5)S, the regioselective substitution of the thio­phene is confirmed with the amine and the amide at the 2- and 5-positions, respectively. In the mol­ecule, the thio­phene ring is twisted by 12.82 (3)° with respect to the aromatic ring of the benzamido group. Intra­molecular N—H⋯O hydrogen bonds are present involving the N atoms of the primary amine and the amide groups, forming S(6) ring motifs. In the crystal, centrosymmetrically related mol­ecules are linked by pairs of N—H⋯O hydrogen bonds involving the amide carbonyl O atoms and the primary amine N atoms to form dimers of R (2) (2)(16) ring motif.