619-05-6

brown powder

The 3,4-diaminobenzoic acid (3,4DAB) crystallizes in the monoclinic C2/c space group with a = 22.564(5), b = 3.940(1), c = 15.176(3) Å and β = 103.99(3)°. As can be seen in Fig.1 the acid appears in the solid state in the zwitterion form like natural existing amino acids. The proton of carboxylate group is moved to the amino group in the meta position of benzene ring.

3,4-Diaminobenzoic acid undergoes cyclocondensations to form, for example, quinoxalines1 and benzimidazoles. It acts as a redox label for electrochemical detection of single base mismatches.

reaction type: solution phase peptide synthesis

Crystallise it from H2O or toluene. [Beilstein 15 IV 1503.]