13C-NMR study of 4-azasteroids in solution and solid state

Structural Study of Polymorphs and Solvates of Finasteride

“…However, CH 2 resonances are usually relatively broad for steroids 34,35 (as in the present case) unless proton decoupling is especially efficient. 36 The spectra of the two forms are consistent with those published previously 21,22 but appear to be of better quality. The chemical shifts are reported in Table 3.…”

“…0.3-0.4 ppm. higher 22 and by Morzycki et al 21 We have confirmed the solution-state assignment of the signals to C3 and C20 by recording a two-dimensional HETCOR (gHMBC) spectrum. Morzycki et al 21 briefly compared solution-state and solid-state chemical shifts for finasteride.…”

“…26,27 Use of dichloromethane/ petroleum ether as the solvent resulted in Figure 1. Relationships between the polymorphs and solvates of finasteride as given in the literature, [18][19][20][21][22][23][24] modified and expanded by the research described in the present article. a mixture of Forms I8 and II.…”

“…They have also been the subject of articles in the research literature. [21][22][23][24] Their crystal structures appear in the Cambridge Crystal Structure Database (CSD) under the codes WOLXOK01 and WOLXOK02 for Form I8 and WOLXOK03 for Form II. Form I8 is orthorhombic, whilst Form II is monoclinic.…”

“…The ethyl acetate molecules were found to be ''disordered in channels.'' 23 A dioxane solvate has also been described and its 13 C CPMAS STRUCTURAL STUDY OF FINASTERIDE SOLID FORMS spectrum illustrated 21 , but its crystal structure has not been published nor was its powder XRD reported.…”