Low-temperature study of a new nevirapine pseudopolymorph.

THE TITLE COMPOUND (SYSTEMATIC NAME: 11-cyclo-propyl-4-methyl-5,11-dihydro-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepin-6-one butanol 0.3-solvate), C(15)H(14)N(4)O·0.3C(4)H(9)OH, was crystallized in a new triclinic pseudopolymorphic form, a butanol solvate, and the crystal structure determined at 150 K. The mol-ecular conformation of this new form differs from that reported previously, although the main inter-molecular hydrogen-bond pattern remains the same. N-H⋯O hydrogen bonds [N⋯O = 2.957 (3) Å] form centrosymmetric dimers and the crystal packing of this new pseudopolymorph generates infinite channels along the b axis.