3′-(4-Methoxyphenyl)-4′-phenyl-3H,4′H-spiro[1-benzothiophene-2,5′-isoxazol]-3-one

In the title compound, C23H17NO3S, the thiophene and isoxazole rings each have an envelope conformation with the spiro C atom linking them forming the flap of the envelope in each case. The dihedral angle between the mean planes of the benzothiophene ring and isoxazole rings is 81.35 (7)°. In the crystal, an intermolecular C—H⋯O hydrogen bond links the molecules into a chain running parallel to the a axis.

In the title compound, C 23 H 17 NO 3 S, the thiophene and isoxazole rings each have an envelope conformation with the spiro C atom linking them forming the flap of the envelope in each case. The dihedral angle between the mean planes of the benzothiophene ring and isoxazole rings is 81.35 (7) . In the crystal, an intermolecular C-HÁ Á ÁO hydrogen bond links the molecules into a chain running parallel to the a axis.

D-HÁ
C 23 H 17 NO 3 S, Figure 1, is the product of the reaction of the p-anisylnitriloxide with (Z)-2-benzylidenebenzo[b]thiophen-3(2H)-one. The X-ray crystal structure study shows that the hydrogen atom attached to C9 is cis to the carbonyl group attached to C7.
The thiophene and isoxazole rings have envelope conformations, the spiro carbon atom linking them forming the flap of the envelope in each case.

Experimental
In a 100 ml flask, 2 mmoles of the (Z)-2-arylidenebenzo[b]thiophen-3(2H)-one and 2.2 mmoles of p-anisyloxime were dissolved in 20 ml of chloroform. The mixture was cooled to 0°C under magnetic stirring in an ice bath. Then 15 ml of bleach (NaOCl) at 24°Chl(chlorometric degree) was added in small amounts without exceeding the temperature of 5°C. The mixture was left under magnetic stirring for 4 h at room temperature, washed with water until pH was neutral and dried on sodium sulfate. The solvent was evaporated using a rotary evaporator and the oily residue dissolved in ethanol. The resulting precipitate was then re-crystallized in ethanol.

Refinement
The H atoms bound to C were treated as riding with their parent atoms [C-H distances are 0.93Å for CH groups with U iso (H) = 1.2 U eq (C), and 0.97 Å for CH3 groups with U iso (H) = 1.5 U eq (C).
Hall symbol: -P 1 Mo Kα radiation, λ = 0.71073 Å a = 9.3644 (13) Å Cell parameters from 312 reflections b = 9.8132 (14)  as those based on F, and R-factors based on ALL data will be even larger.