Crystal structure of 7-chloro-3-isopropylsulfanyl-4H- 1,2,4-benzothiadiazine 1,1-dioxide, C10H11CIN2O2S2

C10H12CIN3O2S, monoclinic, P12i/nl (no. 14), a = 5.898(1) A, b = 17.148(3) A, c = 12.506(2) A, β = 94.41(1)°, V= 1261.2 A, Z = 4, RpfF) = 0.043, wRretfF) = 0.110, Τ = 293 Κ. Source of material The compound was synthesized by a well described four steps chemical pathway starting from 4-chloroaniline [1]. Crystals were obtained by slow evaporation of a methanol solution. Experimental details Η atoms were restrained (included as riding atoms) except H(N4) and H(N11) which were refined, with isotropic temperature parameters fixed at 1.2 Ueq of the parent atom (1.5 for methyl atoms). Discussion 7-Chloro-3-isopropylamino-4f/-1,2,4-benzothiadiazine 1,1 -dioxide, namely BPDZ73, was revealed to be one of the most potent and tissue-selective pancreatic B-cells ATP sensitive potassium channel opener [1,2]. Some crystallographic structures of related compounds have been determined such as 7-iodo-3-isopropylamino-4/M ,2,4-benzothiadiazine 1,1-dioxide (BPDZ69) [3] which is less powerful and less sensitive at the level of the pancreatic tissue. X-ray analysis of chloroand iodo-substituted compounds demonstrated that the N4—C3 distances [1.352(4) A and 1.367(8) A] correspond to a single bond type. The AHrather than the 2Htautomer form is so exhibited in the crystalline state of the two compounds like in many benzothiadiazine 1,1-dioxides previously studied. The presence of N4-H—Ο hydrogen bond in both structures confirms this scheme. It must be emphasized that all H(N) hydrogen positions were located by Fourier difference synthesis, and included in the refinements. Moreover, there are no significant peaks near N2 in the difference maps. In the crystal structure ofBPDZ73,theN2—C3[1.330(4)A]andC3—Nil [1.314(4)A] bond lengths indicate a charge derealization along the N2-C3-N11-H Ol bonds network as observed in the structure of BPDZ69 [3]. Although the symmetry in both structures is described by the same space group Pl2\/nl, the packing modes are quite different Indeed the hydrogen-bonding scheme in BPDZ73 involves the N4-H4-02' and N11-H1 l O l ' bonds [symmetry code (i) Vt+x,Vi-y,¥t+z)], with distances N4-02' 2.811(3) A, Nil—Ol' 2.976(3) A, and angles N4-H4-02' 169(3)°, N11-H1 l-Ol' 177(4) The other shortest intermolecular contact is Cll O l 3.593(4) A [(ii) -l+x.y ,z]. Whereas the stacking of the molecules in the BPDZ69 structure is characterized by three Η-bonds Ν4-Η4-01, N4-H4 01, Nll-Hll-OlTM, and by the other close intermolecular contacts N4—N4 [3.281(8) Α], Ο Ι Ο Γ [3.172(8) A] and 11-02 [3.258(7) A] [(iii) \-x,2-y-z; (iv) l+x.y.z; (v): -x,2-y-z; (vi) -x,2-y, 1-z], The values of the torsion angles inside the heterocycle shows that the BPDZ73 molecule conformation is more plane than that of BPDZ69. Table 1. Data collection and handling.