Low-temperature study of a new nevirapine pseudopolymorph

Area of Science:

• Crystallography
• Solid-state chemistry
• Materials science

Background:

• Polymorphism and solvatomorphism are critical in pharmaceutical development.
• Understanding crystal structures aids in predicting and controlling material properties.
• Previous crystal forms of the title compound have been reported.

Purpose of the Study:

• To crystallize and determine the crystal structure of a new pseudopolymorphic form of 11-cyclopropyl-4-methyl-5,11-dihydro-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepin-6-one butanol 0.3-solvate.
• To analyze the molecular conformation and intermolecular interactions in this new crystal form.
• To compare the new form with previously reported crystal structures.

Main Methods:

• Single-crystal X-ray diffraction at 150 K.
• Crystallization techniques to obtain the butanol solvate.
• Structural analysis of the obtained crystal form.

Main Results:

• A new triclinic pseudopolymorphic form, a butanol solvate (C(15)H(14)N(4)O·0.3C(4)H(9)OH), was successfully crystallized.
• The molecular conformation in this new form differs from previously reported structures.
• The crystal packing features N-H⋯O hydrogen bonds forming centrosymmetric dimers and generating infinite channels along the b axis.

Conclusions:

• The study successfully identified and characterized a novel pseudopolymorphic butanol solvate of the title compound.
• The distinct molecular conformation and packing highlight the complexity of solid-state behavior for this compound.
• The formation of channels suggests potential applications in host-guest chemistry or material design.