Two N-substituted 3,5-diphenyl-2-pyrazoline-1-thiocarboxamides.

The structures of N-ethyl-3-(4-fluoro­phen­yl)-5-(4-methoxy­phen­yl)-2-pyrazoline-1-thio­carboxamide, C₁₉H₂₀FN₃OS, (I), and 3-(4-fluoro­phen­yl)- N-methyl-5-(4-methyl­phen­yl)-2-pyrazoline-1-thio­carboxamide, C₁₈H₁₈FN₃S, (II), have similar geometric parameters. The meth­oxy/methyl-substituted phenyl groups are almost perpendicular to the pyrazoline (pyraz) ring [inter­planar angles of 89.29 (8) and 80.39 (10)° for (I) and (II), respectively], which is coplanar with the fluoro­phenyl ring [inter­planar angles of 5.72 (9) and 10.48 (10)°]. The pyrazoline ring approximates an envelope conformation in both structures, with the two-coordinate N atom involved in an intra­molecular N—H⋯N_pyraz inter­action. In (I), N—H⋯O and C—H⋯S inter­molecular hydrogen bonds are the primary inter­actions, whereas in (II), there are no intermolecular hydrogen bonds. [ABSTRACT FROM AUTHOR]