Crystal structure of (tert-butylcarbamoyl)(4-chloro-2-oxo-2H-chromen-3-yl)methyl acetate

In the title compound, C17H18ClNO5, which was synthesized by reacting 4-chloro-3-formylcoumarin, acetic acid and tert-butyl isocyanide, the acetamido side chain is convoluted with ring-to-side chain C—C—C—C, C—C—C—N and C—C—N—C torsion angles of −123.30 (14), −135.73 (12) and 176.10 (12)°, respectively. In the crystal, N—H⋯O and weak C—H⋯O hydrogen bonds are present, which together with π–π coumarin-ring interactions [ring centroid separations = 3.4582 (8) and 3.6421 (9) Å], give rise to a layered structure lying parallel to (001).


S2. Experimental
The title compound was synthesized as follows. A solution of 4-chloro-3-formyl coumarin (1 mmol), acetic acid (1 mmol) and t-butyl isocyanide (1 mmol) in 10 ml of benzene were refluxed at 80 0 C for 40h. The volatiles were removed under reduced pressure. The crude reaction mixture was subjected to column chromatography using an EtOAc/hexane mobile phase. The compound was isolated as a white colored solid with 70% yield. Single crystals of the title compound (m.p. 195-197 °C) suitable for X-ray analysis were obtained by slow room temperature evaporation of a dichloromethane  168,165,158,152,150,133,126,125,122,118,116,70,52,28,20; LCMS: MH + , 350.

S3. Refinement
All hydrogen atoms on aromatic C atoms and the N atom were placed in calculated positions and refined using a riding model, with C-H = 0.93-0.96 Å and N-H = 0.86 Å and with U iso (H) = 1.2U eq (aromatic C and N) or 1.5 U eq (methyl C).
One reflection was considered to be affected by the beamstop.  Molecular configuration and atom-numbering scheme for the title compound with displacement ellipsoids drawn at the 50% probability level.

Figure 2
Crystal packing diagram of the title compound, viewed along the c axis, with hydrogen atoms omitted for clarity.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.