Synthesis and Crystal Structures of α-Phenyl- and α-Trifluoromethyl-α-(2-pyridyl-N-oxide)ethanols and α-Phenyl-α-(2-pyridyl-N-oxide)ethylene
作者:Barbara Modec、Michel Stephan
DOI:10.1007/s10870-010-9894-4
日期:2011.3
The X-ray structures of two α-substituted α-(2-pyridyl-N-oxide)ethanols, the α-phenyl- (3a) and α-trifluoromethyl- (3b) derivatives, were determined. On dehydration of 3a, compound 4a was obtained. This study brought a clear proof that the α-(2-pyridyl-N-oxide)ethanols are formed following oxidation with peroxides of their corresponding pyridines. A different molecular packing was observed for the α-trifluoromethyl derivative due to an additional hydrogen bonding. Compound 3a crystallized in the monoclinic space group P 21/n with unit cell parameters a = 5.7416(1) Å, b = 14.3841(4) Å, c = 13.2821(3) Å, β = 94.918(2)°, V = 1092.90(4) Å3, Z = 4, D = 1.308 Mg/m3. Compound 3b crystallized in the triclinic space group P −1 with unit cell parameters a = 6.1209(2) Å, b = 8.1938(4) Å, c = 9.4675(4) Å, α = 73.363(3)°, β = 73.166(3)°, γ = 71.659(3)°, V = 421.32(3) Å3, Z = 2, D = 1.633 Mg/m3. Compound 4a crystallized in the monoclinic space group P 21/n with unit cell parameters a = 9.3579(3) Å, b = 12.7340(3) Å, c = 9.8579(3) Å, β = 117.3249(15)°, V = 1043.63(5) Å3, Z = 4, D = 1.255 Mg/m3. The X-ray crystal structures of the title α-(2-pyridyl-N-oxide)ethanols were determined bringing a clear proof that these compounds are formed following the oxidation using peroxides of their corresponding pyridines. A different molecular packing was observed for the α-trifluoromethyl derivative due to an additional hydrogen bonding.
确定了两种α-取代的α-(2-吡啶基-N-氧化物)乙醇,α-苯基-(3a)和α-三氟甲基-(3b)衍生物的X射线结构。 3a脱水后,得到化合物4a。这项研究清楚地证明了α-(2-吡啶基-N-氧化物)乙醇是在用相应吡啶的过氧化物氧化后形成的。由于额外的氢键,α-三氟甲基衍生物观察到不同的分子堆积。化合物 3a 在单斜空间群 P 21/n 中结晶,晶胞参数 a = 5.7416(1) Å, b = 14.3841(4) Å, c = 13.2821(3) Å, β = 94.918(2)°, V = 1092.90(4) Å3,Z = 4,D = 1.308 Mg/m3。化合物 3b 在三斜空间群 P -1 中结晶,晶胞参数 a = 6.1209(2) Å, b = 8.1938(4) Å, c = 9.4675(4) Å, α = 73.363(3)°, β = 73.166 (3)°,γ = 71.659(3)°,V = 421.32(3) Å3,Z = 2,D = 1.633 Mg/m3。化合物 4a 在单斜空间群 P 21/n 中结晶,晶胞参数 a = 9.3579(3) Å, b = 12.7340(3) Å, c = 9.8579(3) Å, β = 117.3249(15)°, V = 1043.63(5) Å3,Z = 4,D = 1.255 Mg/m3。确定了标题α-(2-吡啶基-N-氧化物)乙醇的X射线晶体结构,清楚地证明这些化合物是在使用其相应吡啶的过氧化物氧化后形成的。由于额外的氢键,α-三氟甲基衍生物观察到不同的分子堆积。