The crystal and molecular structure of 3-(2-diethylammoniumethoxy)-1,2-benzisothiazole tetrachlorocuprate

N-[(3-Methyl-1-phenylsulfonyl-1H-indol-2-yl)methyl]-1,1-dioxo-1-benzo[d]isothiazol-3(2H)-one

“…1), the sulfonyl-bound phenyl ring and thiazole group make dihedral angles of 79.2 (1) and 88.6 (1) , respectively, with the indole mean plane. All bond lengths and angles are comparable with those observed in phenylsulfonylindoles (Ravishankar et al, 2005a,b) and benzothiazole (Bonamartini et al, 1971). The N-Csp 2 bond lengths [N1-C2 = 1.430 (3) Å , N1-C5 = 1.419 (3) Å ] are significantly longer than the mean value of 1.355 (14) Å reported for N atoms with planar configuration (Allen et al, 1987) because of the electron-withdrawing character of the phenylsulfonyl group.…”

Structural characteristics of isoxazol-3-ol and isothiazol-3-ol, carboxy group bioisosteres examined by X-ray crystallography and ab initio calculations

“…The geometries of 3 and 5 are comparable to earlier observations for nonionized isoxazol-3-ols, 11 whereas there are only scarce literature data for comparison with the structures of 4 and 6. Thus, a search of the Cambridge Structural Database 12 for compounds containing the isothiazol-3-ol moiety resulted in five hits (AEBZTZ, 13 EABZIT, 14 HMSPTZ, 15 JIGCIL 16 and YEMLOR 17 ), only one (HMSPTZ) containing the free 3-hydroxy group in a substituted isothiazole ring. Substitution of sulfur for oxygen in the heterocyclic ring (3→4 and 5→6) has little effect on the ring geometry, except for that imposed by the larger covalent radius of the sulfur atom.…”

“…However, the displacement of neighbouring stacks still causes the heterocyclic rings to tilt strongly with respect to the stacking direction. 13 C NMR titrations of 3 and 4 gave monophasic titration curves defined by eqn. (1), where δ i is the observed chemical shift of the i-th carbon at any pH, δ i 0 and δ i 1 are the chemical shifts of the i-th carbon in the nonprotonated and monoprotonated species, and K a is the acid-base equilibrium constant.…”

“…Since the carbon resonances of 3 and 4 were well resolved, both heterocycles could be titrated simultaneously, which made the pK a difference obtained independent of errors in pH readings. The 13 C{ 1 H} NMR spectra were recorded at 25 ЊC with a Bruker AMX 400 WB spectrometer operating at 100.62 MHz for 13 C. The spectra were standardized to internal 3-(trimethylsilyl)propanesulfonate. The nonlinear curve fitting was carried out with Ultrafit ver.…”

“…8 The corresponding isothiazol-3-ol analogues 12 and 14 have recently been synthesized, and were shown to be selective AMPA receptor agonists. 9 Thio-AMPA (12) turned out to be a weaker agonist than AMPA (11), whereas thio-ATPA (14) was found to be more potent than ATPA (13).…”