Crystal structures of N-(pyridin-2-ylmeth-yl)pyrazine-2-carboxamide (monoclinic polymorph) and N-(pyridin-4-ylmeth-yl)pyrazine-2-carboxamide.

ABSTRACT: The title compounds, C11H10N4O (HL1) and C11H10N4O (HL2), are pyridine 2-ylmethyl and 4-ylmethyl derivatives, respectively, of pyrazine-2-carboxamide. HL1 was measured at 153?K and crystallized in the monoclinic space group P21/c with Z = 4. There has been a report of the same structure measured at room temperature but assumed to crystallize in the triclinic space group P-1 with Z = 4 [Sasan et al. (2008 ?). Monatsh. Chem. 139, 773-780]. In HL1, the pyridine ring is inclined to the pyrazine ring by 61.34?(6)°, while in HL2 this dihedral angle is 84.33?(12)°. In both mol-ecules, there is a short N-H?N inter-action involving the pyrazine carboxamide unit. In the crystal of HL1, mol-ecules are linked by N-H?N hydrogen bonds, forming inversion dimers with an R 2 (2)(10) ring motif. The dimers are linked via bifurcated-acceptor C-H?O hydrogen bonds, forming sheets lying parallel to (102). The sheets are linked via C-H?N hydrogen bonds, forming a three-dimensional structure. In the crystal of HL2, mol-ecules are linked by N-H?N and C-H?N hydrogen bonds to form chains propagating along [010]. The chains are linked via C-H?O hydrogen bonds, forming sheets lying parallel to (100). Within the sheets there are ?-? inter-actions involving neighbouring pyrazine rings [inter-centroid distance = 3.711?(15)?Å]. Adjacent sheets are linked via parallel slipped ?-? inter-actions involving inversion-related pyridine rings [inter-centroid distance = 3.6395?(17)?Å], forming a three-dimensional structure.

SUBMITTER: Cati DS 

PROVIDER: S-EPMC4120586 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature