N-(4-Chlorophenyl)-2-(hydroxyimino)acetamide

The title compound, C8H7ClN2O2, is an intermediate in the synthesis of 5-chloroisatin, which can be further transformed to 5-chloro-2-indolinone via a Wolff–Kishne reduction. The C2N acetamide plane forms a dihedral angle of 6.3 (3)° with the benzene ring. An intramolecular C—H⋯O interaction results in the formation of a six-membered ring. In the crystal, intermolecular N—H⋯O, N—H⋯N and O—H⋯O hydrogen bonds link the molecules into multimers, forming sheets.

The title compound, C 8 H 7 ClN 2 O 2 , is an intermediate in the synthesis of 5-chloroisatin, which can be further transformed to 5-chloro-2-indolinone via a Wolff-Kishne reduction. The C 2 N acetamide plane forms a dihedral angle of 6.3 (3) with the benzene ring. An intramolecular C-HÁ Á ÁO interaction results in the formation of a six-membered ring. In the crystal, intermolecular N-HÁ Á ÁO, N-HÁ Á ÁN and O-HÁ Á ÁO hydrogen bonds link the molecules into multimers, forming sheets.

Structure Reports Online
In the title compound (Fig 1), the bond lengths and angles are within normal ranges. The central acetamide plane N1/ C7/O1/C8 forms a dihedral angle of 6.3 (3)° with the phenyl ring. An intramolecular C-H···O interaction results in the formation of a six-membered ring. In the crystal packiing, intermolecular N-H···O and N-H···N hydrogen bonds (Table   1) link the molecules into multimers (Fig. 2), ithat may be effective in the stabilization of the structure.
Experimental 85 g (0.06 mol) sodium sulfate and 300 ml water were added to a 1000 ml 3 mouthed flask, mixed until the sodium sulfate dissolved following which a saturated solution of 18 g (0.11 mol) chloral hydrate was added. While stirring, a mixture of 12.7 g(0.1 mol) p-chloroaniline, 12 ml hydrochloric acid and 100 ml water was added dropwise causing a white precipitate.
Then 22 g(0.32 mol) hydroxylamine hydrochloride was added and the mixture was heated to 348k. After 5 h, a light yellow precipitate appeared which was filtered and washed with water, dried and recrystallized from ethanol (yield 90.2%). Crystals suitable for X-ray analysis were obtained by slow evaporation of an acetone solution (yield; 90%, m.p. 443 K).

Data collection
Enraf-Nonius CAD-4 diffractometer R int = 0.031 Radiation source: fine-focus sealed tube θ max = 25.3º Monochromator: graphite θ min = 2.0º T = 293 K h = 0→12 ω/2θ scans k = 0→10 Absorption correction: ψ scan (North et al., 1968) l = −24→24 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 Rfactors(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.