Trimethyl (5SR,6SR)-1,3-dichloro-8-diethyl-amino-5,6-dihydro-5-hydroxyisoquinoline-5,6,7-tricarboxylate

The title compound, C19H22Cl2N2O7, has four independent molecules in the as ymmetric unit with no pseudosymmetry. In each of the four molecules the fus ed cyclohexadiene ring adopts a skew-boat conformation, with two of the thr ee methoxycarbonyl groups in the axial orientation and the third methoxycar bonyl and the diethylamino groups attached equatorially. The hydroxyl group s are involved in O-H ... O intermolecular hydrogen bonds with carbonyl-O a toms to form infinite chains in the [2 (1) over bar 0] direction.