4-(3-Fluoro-4-methylanilino)-2-methylidene-4-oxobutanoic acid

The title compound, C12H12FNO3, crystallizes with two independent molecules (A and B) in the asymmetric unit. The dihedral angle between the mean planes of the 3-fluoro-4-methylphenyl ring and the oxoamine group is 25.7 (7)° in molecule A and 71.3 (7)° in molecule B, while the mean plane of the 2-methylidene-4-oxobutanoic acid group is twisted by 76.2 (1)° from that of the oxoamine group in molecule A and by 76.2 (4)° in molecule B. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds [the latter forming an R 2 2(8) graph-set motif] link the molecules into a two-dimensional network parallel to the ac plane.

The title compound, C 12 H 12 FNO 3 , crystallizes with two independent molecules (A and B) in the asymmetric unit. The dihedral angle between the mean planes of the 3-fluoro-4methylphenyl ring and the oxoamine group is 25.7 (7) in molecule A and 71.3 (7) in molecule B, while the mean plane of the 2-methylidene-4-oxobutanoic acid group is twisted by 76.2 (1) from that of the oxoamine group in molecule A and by 76.2 (4) in molecule B. In the crystal, N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds [the latter forming an R 2 2 (8) graph-set motif] link the molecules into a two-dimensional network parallel to the ac plane.   Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) Àx; Ày þ 1; Àz þ 1; (ii) Àx þ 1; Ày þ 2; Àz þ 1; (iii) x; y À 1; z; (iv) x þ 1; y; z. BN thanks the UGC for a BSR one-time grant for the purchase of chemicals and the DST-PURSE for financial assistance. HSY thanks the University of Mysore for research facilities. JPJ acknowledges the NSF-MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.

Comment
Itaconic anhydride (ITA) is a monomer obtained from renewable resources. Copolymers containing both hydrophilic and hydrophobic segments are drawing considerable attention because of their possible use in biological systems. N-Substituted itaconamic acids are strongly amphiphilic molecules. Itaconic anhydride is more reactive than maleic anhydride and is an alternative monomer for introducing polar functionality into polymers (Oishi, 1980;Urzua et al., 1998). The basic skeleton of itaconic anhydride is useful for the synthesis of various biodynamic cyclic derivatives such as imides (Shetgiri & Nayak, 2005), pyridazine (Katla et al., 2011), oxazepine (Hanoon, 2011 and oxobutanoic acid (Nayak et al., 2013) derivatives. Hence in view of the importance of anhydride derivatives, the crystal structure of the title compound, C 12 H 12 NO 3 F, (I), is reported here.
The title compound, (I), crystallizes with two independent molecules (A & B) in the asymmetric unit (Fig. 1). The dihedral angle between the mean planes of the 3-fluoro-4-methylphenyl ring and the oxo-amine group is 25.7 (7)° (A) and 71.3 (7)Å (B), while the mean plane of the 2-methylidene-4-oxobutanoic acid group is twisted by 76.2 (1)Å (A) and 76.2 (4)Å (B) from that of the oxo-amine group. In the crystal, N-H···O hydrogen bonds and O-H···O R 2 2 (8) graph set motif hydrogen bonds link the molecules into a 2-D network along the ac plane ( Fig. 2) and influence crystal packing.

Experimental
Itaconic anhydride (0.112 g, 1 mmol) dissolved in a 30 ml acetone and it was stirred at ambient temperature and 3fluoro-4-methyl aniline (0.125 g, 1 mmol) was added portion wise over 30 mins (Fig. 3) The mixture turned into yellow slurry. After stirring 1.5hrs, the slurry was filtered. The solid was washed with acetone and dried to give title compound (I). Single crystals were grown from methanol by the slow evaporation method and used as such for x-ray studies.(M.P.: 414-416 K).

Refinement
All of the H atoms were placed in their calculated positions and then refined using the riding model with Atom-H lengths of 0.93Å (CH), 0.97Å (CH 2 ), 0.96Å (CH 3 ), 0.82Å (OH) or 0.86Å (NH). Isotropic displacement parameters for these atoms were set to 1.2 (CH, CH 2 , NH) or 1.5 (CH 3 , OH) times U eq of the parent atom. Idealised Me and tetrahedral OH refined as rotating groups.    Synthesis scheme of (I).