摘要
To determine the structure of o-methylisourea for instructing its application and factory production, crystalline o-methylisourea hydrosulfate was synthesized in this paper by methylation of urea with dimethylsulfate, followed by acidification in 53% yield. Its single crystal prepared from 95% ethanol is determined by X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 8.5330（10）, b = 7.0548（9）, c = 11.6764（14） A°, β = 95.429（2）°, Mr = 172.16, V= 699.75（15）A°^3, Dc = 1.634 g/cm^3, Z = 4, F（000） = 360 andμ（MoKα） = 0.435 mm^-1. Of 1511 unique reflections, 1294 is gotten （I 〉 2σ（I））. The structure was solved by Fourier method and refined to R = 0.0438 and wR = 0.1209. The crystal structure shows that o-methylisourea combines with bisulfate via the intramolecular hydrogen bond between N（2）-H（4） of o-methylisourea and O（2） of bisulfate. As a result, the molecular structure is [H2NC（OCH3）NH2]HSO4 and the formula is C2H8N2O5S or C2H7N2O·HSO4 but not H2NC（OCH3）NH-HSO4 or H2NC（OCH3）NH·0.5H2SO4.
To determine the structure of o-methylisourea for instructing its application and factory production, crystalline o-methylisourea hydrosulfate was synthesized in this paper by methylation of urea with dimethylsulfate, followed by acidification in 53% yield. Its single crystal prepared from 95% ethanol is determined by X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 8.5330（10）, b = 7.0548（9）, c = 11.6764（14） A°, β = 95.429（2）°, Mr = 172.16, V= 699.75（15）A°^3, Dc = 1.634 g/cm^3, Z = 4, F（000） = 360 andμ（MoKα） = 0.435 mm^-1. Of 1511 unique reflections, 1294 is gotten （I 〉 2σ（I））. The structure was solved by Fourier method and refined to R = 0.0438 and wR = 0.1209. The crystal structure shows that o-methylisourea combines with bisulfate via the intramolecular hydrogen bond between N（2）-H（4） of o-methylisourea and O（2） of bisulfate. As a result, the molecular structure is [H2NC（OCH3）NH2]HSO4 and the formula is C2H8N2O5S or C2H7N2O·HSO4 but not H2NC（OCH3）NH-HSO4 or H2NC（OCH3）NH·0.5H2SO4.
基金
This work was supported by the National Natural Science Foundation of China (Nos. 30171070 and 30371632)
