N-Acryloyl glycinamide

The molecule of the title compound [systematic name: N-(carbamoylmethyl)prop-2-enamide], C5H8N2O2, which can be radically polymerized to polymers with thermoresponsive behavior in aqueous solution, consists of linked essentially planar acrylamide and amide segments [maximum deviations = 0.054 (1) and 0.009 (1) Å] with an angle of 81.36 (7)° between their mean planes. In the crystal, N—H⋯O hydrogen bonding leads to an infinite two-dimensional network along (100).

The molecule of the title compound [systematic name: N-(carbamoylmethyl)prop-2-enamide], C 5 H 8 N 2 O 2 , which can be radically polymerized to polymers with thermoresponsive behavior in aqueous solution, consists of linked essentially planar acrylamide and amide segments [maximum deviations = 0.054 (1) and 0.009 (1) Å ] with an angle of 81.36 (7) between their mean planes. In the crystal, N-HÁ Á ÁO hydrogen bonding leads to an infinite two-dimensional network along (100).
Experimental N-acryloyl glycinamide has been prepared according to the route of Haas and Schuler (1964). However, reagent ratios, workup and purification have been modified as follows.
In a 1 l three-necked round-bottom flask equipped with a mechanical stirrer glycinamide hydrochloride (23.11 g, 209 mmol) and potassium carbonate (56.7 g, 410 mmol) were dissolved in 125 ml of water. The solution was cooled in an ice bath and acryloyl chloride (16.65 ml, 205 mmol) dissolved in 250 ml of diethylether was added dropwise over 30 min with fast stirring (300 rpm). The suspension was further stirred at RT for 2 h. The diethylether was removed by rotary evaporation at 35 °C. The remaining aqueous phase was freeze dried. The crude brittle solid was extracted with acetone (6 times, 500 ml acetone, 40 °C, stirring for at least 15 min). Insoluble potassium salts were filtered off and the acetone was removed by rotary evaporation at 35 °C. 22.7 g (85%) of crude product were obtained. The crude product was dissolved in an eluent mixture of methanol and dichloromethane (v/v = 1/4, 600 ml) by heating to reflux once. The solution was filtered to remove polymeric impurities and purified by column chromatography (d = 9 cm, 900 g silica, porosity 60 Å, 0.063-0.2 mm mesh size, TLC: R f (N-acryloyl glycinamide) = 0.40) to obtain 21.3 g (80%) of product which was recrystallized from 240 ml of a mixture of methanol and acetone (v/v = 1/2) to yield 15.3 g (57%) of colorless needle-like crystals.
supplementary materials sup-2 For obtaining crystals that are suitable for X-ray analysis a small fraction of purified N-acryloyl glycinamide was again recrystallized from a dilute solution in 2-propanol.

Refinement
All H atoms were located in a difference Fourier map and refined isotropically. The C-H bond distances vary from 0.937 (18)

Special details
Experimental Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional  (17)