4-Ethoxybenzohydrazide

The title compound, C9H12N2O2, is approximately planar (r.m.s. deviation = 0.13 Å for all non-H atoms). The carbonyl O atom is involved as acceptor in three different hydrogen-bond interactions. One N—H⋯O and the C—H⋯O(carbonyl) contact together with a weak C—H⋯O(ethoxy) interaction link the molecules into sheets parallel to (102). These are further linked into a three-dimensional network via the remaining C—H⋯O(carbonyl) hydrogen bond and a C(methylene)—H⋯π interaction


Experimental
3.6 g of methyl p-ethoxybenzoate was added to 40 ml freshly distilled methanol in a round-bottomed flask. The content was stirred until completely dissolved and the flask was fitted with a reflux condenser bearing a calcium chloride guard tube. Then 2.0 g of 80% hydrazine hydrate was added slowly. The reaction was monitored by thin layer chromatography.
Upon completion of the reaction, the content was concentrated in vacuo (Furniss et al., 1989). The resulting crude solid was filtered, washed with water and agitated with freshly distilled acetone for 1 h. The product was then recrystallized from aqueous ethanol.

Refinement
The NH hydrogen atoms were refined freely. Methyl H atoms were identified in difference syntheses, idealized and refined corresponding to a rigid group with C-H 0.98 Å and H-C-H angles 109.5°, allowed to rotate but not tip.
Other H atoms were placed in calculated positions and refined using a riding model with C-H arom = 0.95 and C-H methylene =0.99 Å; the hydrogen U values were fixed at 1.5 (methyl) or 1.2 × U(eq) of the parent atom.

Computing details
Data

4-Ethoxybenzohydrazide
Crystal data Rms deviation of fitted atoms = 0.0001 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.