Ethyl 3-[7-ethoxy-6-(4-methoxybenzenesulfonamido)-2H-indazol-2-yl]propanoate

In the title compound, C21H25N3O6S, the dihedral angle between the methoxybenzene and indazole rings is 74.96 (5)°. The crystal packing is stabilized by an N—H⋯O hydrogen bond into a two-dimensional network. In addition, C—H⋯π interactions and a π–π contact, with a centroid–centroid distance of 3.5333 (6) Å, are observed. The crystal packing is stabilized by N—H⋯O and C—H⋯O hydrogen bonds.

In the title compound, C 21 H 25 N 3 O 6 S, the dihedral angle between the methoxybenzene and indazole rings is 74.96 (5) . The crystal packing is stabilized by an N-HÁ Á ÁO hydrogen bond into a two-dimensional network. In addition, C-HÁ Á Á interactions and acontact, with a centroid-centroid distance of 3.5333 (6) Å , are observed. The crystal packing is stabilized by N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds.
Two neighbouring molecules generate a hydrogen-bonded dimer about a center of inversion through a pair of intermolecular N-H···O interactions (Table 1 and Fig. 2).

Experimental
A mixture of ethyl 3-(6-nitro-2H-indazol-2-yl)propanoate (1.22 mmol) and anhydrous SnCl 2 (1.1 g, 6.1 mmol) in 25 mL of absolute ethanol was heated at 60 °C for 3 h. After reduction, the starting material disappeared, and the solution was allowed to cool down. The pH was made slightly basic (pH 7-8) by addition of 5% aqueous potassium bicarbonate before extraction with ethyl acetate. The organic phase was washed with brine and dried over magnesium sulfate. The solvent was removed to afford the amine, which was immediately dissolved in pyridine (5 ml) and then reacted with 4-methoxybenzenesulfonyl chloride (1.25 mmol) at room temperature for 24 h. After the reaction mixture was concentrated in vacuo, the resulting residue was purified by flash chromatography (eluted with Ethyl acetate: Hexane 1:9).

Refinement
The H atoms bound to C were positioned geometrically and constrained to ride on their parent atoms [C-H distances are 0.93Å for CH groups with U iso (H) = 1.2 U eq (C,N), and 0.97 Å for CH3 groups, and the coordinates for the H atom bonded to N were taken from a difference map, and the atom was refined using a riding model.       Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.34987 (