Ethyl 2-[(2-oxo-2 H-chromen-6-yl)-oxy]acetate

Abstract

Ethyl 2-[(2-oxo-2H-chromen-6-yl)-oxy]acetate, C₁₃H₁₂O₅, a member of the pharmacologically important class of coumarins, crystallizes in the monoclinic C2/c space group in the form of sheets, within which mol-ecules are related by inversion centers and 2₁ axes. Multiple C-H⋯O weak hydrogen-bonding inter-actions reinforce this pattern. The planes of these sheets are oriented in the approximate direction of the ac face diagonal. Inter-sheet inter-actions are a combination of coumarin system π-π stacking and additional C-H⋯O weak hydrogen bonds between ethyl acet-oxy groups.

Keywords: chromen-2-one; coumarin; crystal structure; sheet structure; weak C—H⋯O H-bonding; π–π stacking.

Figure 1

Displacement ellipsoid plot of ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate with complete labeling of non-hydrogen atoms. Ellipsoids are shown at the 50% probability level.

Figure 2

Planar centrosymmetric dyads of ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate showing the C—H⋯O weak inter­actions that guide the packing arrangement. The H5⋯O4 and H6⋯O3 distances are 2.47 and 2.65 Å, respectively. The symmetry transformation relating mol­ecules through these hydrogen bonds is −x +  , −y +  , −z + 1. Displacement ellipsoids are presented at the 50% probability level.

Figure 3

Rows of ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate mol­ecules to both sides of, and in the same plane as, the centrosymmetric diads in Fig. 2 ▸. These mol­ecules are related to those in the centrosymmetric dyads by a 2₁ operation, the position for one such axis being shown. This patterned arrangement is assisted by C8—H8⋯O1 and by C1—H1⋯O1 close contacts, in which the corresponding H8⋯O1 and H1⋯O1 distances are 2.27 and 2.61 Å. The symmetry transformation whereby one mol­ecule is converted to the other across these hydrogen bonds is −x +  , y −  , −z +  . Ellipsoids are shown at the 50% probability level.

Figure 4

Packing diagram for ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate illustrating the arrangement of mol­ecules into sheets in the approximate direction of the ac face diagonal of the unit cell. All H atoms are omitted for clarity, and displacement ellipsoids are drawn at 50% probability.

Figure 5

Weak C—H⋯O inter­actions between centrosymmetric pairs of mol­ecules of ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate in different sheets. The H12A⋯O3 distance is 2.57 Å, and the symmetry transformation relating these mol­ecules is −x + 1, −y + 1, −z + 1. Displacement ellipsoids are presented at the 50% probability level.

Figure 6

Hirshfeld surface for ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate with d _norm set between −0.3446 and 1.3365. Close inter­molecular contacts are depicted with dashed lines.

Figure 7

Fingerprint plot for ethyl 2-[(2-oxo-2H-chromen-6-yl)­oxy]acetate with all inter­molecular contacts presented in the upper left panel and the O⋯H/H⋯O, C⋯H/H⋯C, and H⋯H contacts illustrated in separate panels (clockwise, respectively).