An Orange Form of Coumarin 314

A new form of the title compound, ethyl 2,3,6,7-tetrahydro-11-oxo-1H, 5H, 11H-[1]benzopyrano[6,7,8-ij]quinolizine-10-carboxylate, C₁₈H₁₉NO₄, was recrystallized from ethanol and is orange in colour. The coumarin moiety is planar and the conformation of the ethoxycarbonyl group is different from that of the yellow form. One of the piperidine rings is disordered and the N atom is in a planar configuration. The crystal packing is governed by van der Waals interactions.

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