Crystal structure of 2-methyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one

Abstract

The asymmetric unit of the title compound, C9H7NO2S, contains two crystallographically independent mol­ecules (A and B). Both mol­ecules are almost planar [maximum deviations = 0.047 (1) and 0.090 (1) Å, respectively, for the S atoms] with the oxazole and thio­phene rings being inclined to one another by 2.65 (16)° in mol­ecule A and by 4.55 (15)° in mol­ecule B. In the crystal, the individual mol­ecules are linked via C—H⋯O hydrogen bonds, forming –A–B–A–B– chains along the [10-1] direction. The chains are linked via C—H⋯π and π–π inter­actions [inter­centroid distances = 3.767 (2) and 3.867 (2) Å] involving inversion-related oxazole and thio­phene rings in both mol­ecules, forming a three-dimensional structure.

Structural characterization and DFT studies of an oxazol-5-one derivative

“…Torsion angles also prove this planarity [C4-C5-C6-N1 = 1.1(7)°, C4-C5-C6-C7 = -177.5(4)°, N1-C8-C9-C14 = 1.7(6)° and O1-C8-C9-C10 = 1.7(5)°]. Bond lengths, bond angles and torsion angles are within normal ranges, and are close to those observed for a very similar structures in the literature [34,35].…”

Dihydrooxazolones and dihydroimidazolones derived from acylglycines: syntheses, molecular structures and supramolecular assembly

“…An analogous reaction between acetylglycine and thiophene-2-carbaldehyde, also in the presence of acetic anhydride, gave 2-methyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one, (II), which was refined as a fully ordered structure, with Z 0 = 2 in the space group P2 1 /n (Sharma et al, 2015). This fully ordered model led to some unexpected geometries, in particular, amongst the C-C distances of the thiophene rings, where, in one of the two independent rings, the lengths of the formal single C-C bond and of one of the formal double C C bonds appeared to be identical within experimental uncertainty, suggesting the presence of unmodelled disorder of the usual thiophene type, involving disorder over two sets of atomic sites related by an approximate 180 The molecular structure of compound (I) in the triclinic polymorph, showing the atom-labelling scheme.…”

“…. For the syntheses of compounds (III) and (IV), mixtures of phenylhydrazine (0.01 mol) in glacial acetic acid (30 ml) with either 2-phenyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one [see (A) in Scheme 2] (0.01 mol) for (III) or 2-(4-methylphenyl)-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one [see (B) in Scheme 2] (0.01 mol) for (IV), themselves prepared exactly as for compound (II) (Sharma et al, 2015), were heated under reflux for 3 h (see Scheme 2). The mixtures were allowed to cool to ambient temperature and were then poured into cold water.…”

“…In the original report on compound (II), which used a fully ordered structural model (Sharma et al, 2015), the two selected reference molecules did not form an asymmetric unit connected by a hydrogen bond; however, a simple rearran-gement of the unit-cell contents provides an asymmetric unit in which the two selected molecules are linked by a C-HÁ Á ÁO hydrogen bond (Table 3). Bimolecular aggregates of this type which are related by an n-glide plane are linked by a further C-HÁ Á ÁO hydrogen bond to form a C 2 2 (14) chain running parallel to the [101] direction (Fig.…”

Crystal structure and Hirshfeld surface analysis of (Z)-3-methyl-4-(thiophen-2-ylmethylidene)isoxazol-5(4H)-one

“…A search of the Cambridge Structural Database (CSD, v5.40, last update May 2019;Groom et al, 2016) for the (Z)-4-(thiophen-2-ylmethylidene)isoxazol-5(4H)-one unit gave five hits: 4-(2-hydroxybenzylidene)-3-methylisoxazol-5(4H)-one (AJESAK; Cheng et al, 2009), 2-(naphthalen-1-yl)-4-(thiophen-2-ylmethylidene)-1,3-oxazol-5(4H)-one (ERIXIN; Gü ndog du et al, 2011), (Z)-4-benzylidene-3-methylisoxazol-5(4H)-one (MBYIOZ01; Chandra et al, 2012), 2-methyl-4-(thiophen-2-ylmethylidene)-1,3-oxazol-5(4H)-one (WOYPIL; Sharma et al, 2015) and (Z)-4-(4-hydroxybenzylidene)-3methylisoxazol-5(4H)-one (VIDSAF; Zemamouche et al, 2018).…”