rac-2,3-Diphenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-one 1-oxide

Abstract

In the title compound, C19H14N2O2S, the thiazine ring exhibits a screw-boat pucker. The oxygen atom on the sulfur atom of the ring is pseudo-axial on the thiazine ring. In the crystal, 21screw-related molecules are linked by C—H...Ocarbonylhydrogen bonds, forming helices propagating along theb-axis direction.

Crystal structures of two solvated 2-aryl-3-phenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-ones

“…Along with the previously mentioned structure (Yennawar et al, 2014), we have published a structure of the sulfoxide derivative (Yennawar et al 2017). No other similar structures were found.…”

Crystal structures of the sulfones of 2,3-diphenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one and 2,3-diphenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-one

“…The structures of 1 and 2 both display a screw-boat (pucker) conformation for the four thiazine rings in the two asymmetric units [puckering amplitude Q ranging between 0.616 (4) and 0.6449 (16) A ˚, and the and ' values, after accounting for the absolute conformation transformations, are between 60.7 (4) and 63.02 (16) , and 140.53 (18) and 142.9 (4) , respectively]. The puckering observed is similar to that in the sulfoxides 5 and 6 (Yennawar, Fox et al 2017;Yennawar, Noble et al 2017), but is different from the envelope conformations seen in the sulfides 3 and 4 (Yennawar, Bendinsky et al, 2014;Yennawar, Singh et al, 2014). Each molecule contains one stereogenic center, which lies between the N atom and the SO 2 group of the heterocyclic ring: in the asymmetric unit of 1, C8 has an S configuration and C28 an R configuration, thus generating a racemic pair.…”

Crystal structure of (1S,2S,5R)-5-acetylamino-4-oxo-2,3-diphenyl-1,3-thiazinan-1-ium-1-olate

“…We have reported previously the crystal structure of 2,3-diphenyl-2,3,5,6-tetrahydro-4H-1,3-thiazin-4one 1-oxide (Yennawar et al, 2016). We have also reported recently the crystal structures of 2,3-diphenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one 1-oxide (Yennawar, Fox et al, 2017) and 2,3-diphenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4one 1-oxide (Yennawar, Noble et al, 2017).…”

“…The geometry of a sulfoxide is pyramidal, with a high energy barrier for inversion, making it possible to isolate stable enantiomers (Bentley, 2005). Herein, we report the crystal structure of the sulfoxide of N-[(2S,5R)-4-oxo-2,3diphenyl-1,3-thiazinan-5-yl]acetamide (Yennawar, Singh & Silverberg, 2015), C 18 H 18 N 2 O 3 S, prepared using the method ISSN 2056-9890 we have reported previously for the oxidation of other 2,3diphenyl-1,3-thiazin-4-ones (Yennawar et al, 2016;Yennawar, Noble et al, 2017) and 1,3-thiazolidinones (Yennawar, Hullihen et al, 2015;Cannon et al, 2015). The oxidation of the confirmed enantiopure sulfide N-[(2S,5R)-4-oxo-2,3-diphenyl-1,3-thiazinan-5-yl]acetamide 0.375-hydrate (Yennawar, Singh & Silverberg, 2015), derived from N-acetyl-l-cysteine, yielded a single stereoisomer as the only product.…”