6,7-Diphenyl-5-thia-7-azaspiro[2.6]nonan-8-one 5,5-dioxide

Abstract

The racemic mixture of the title compound, C19H19NO3S, crystallizes in space group P\overline{1} with two homochiral molecules in each asymmetric unit. The seven-membered ring in both molecules is in a pucker-chair conformation. The extended structure exhibits C—H...O hydrogen bonds, of which two connect crystallographically independent molecules to generate a chain propagating along the b-axis direction. One C—H grouping of the cyclopropyl ring is in close contact with the phenyl ring of the neighboring independent molecule in C—H...π type interactions with carbon atom–ring-centroid distances of 3.544 (5) and 3.596 (4) Å. Other interactions are of the parallel–reciprocal type, with the chiral carbon atom of one molecule donating a proton to an oxygen atom of the sulfone group of a symmetry-related molecule and vice-versa. Symmetry-related molecular pairs also exhibit T-type interactions between aromatic rings with interplanar angles of 74.2 (2) and 69.2 (2)° and intercentroid distances of 4.965 (4) and 5.114 (4) Å.

Keywords

• crystal structure
• c—h...o
• c—h...π
• aromatic t-type stacking interactions
• chair pucker