(2R)-2-hydroxy-2-phenylacetic acid;pyridine-3-carboxamide | 951381-60-5

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡啶及其衍生物
• 英文名称: (2R)-2-hydroxy-2-phenylacetic acid;pyridine-3-carboxamide
• CAS: 951381-60-5
• 化学式: C₆H₆N₂O*C₈H₈O₃
• 分子量: 274.276
• InChiKey: OBEVXNAFGQGHJG-OGFXRTJISA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.99
• 重原子数：
  20
• 可旋转键数：
  3
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.07
• 拓扑面积：
  114
• 氢给体数：
  3
• 氢受体数：
  5

反应信息

• 作为产物：
  描述：

  D-扁桃酸 、 烟酰胺 以 乙腈 为溶剂， 生成 (2R)-2-hydroxy-2-phenylacetic acid;pyridine-3-carboxamide
  参考文献：
  名称：

  Formation Enthalpies and Polymorphs of Nicotinamide–R-Mandelic Acid Co-Crystals

  摘要：

  Co-crystals provide an opportunity to improve the properties of pharmaceuticals and other materials. We report a method for determining the formation enthalpies of co-crystals in which enthalpies of melting are measured for a co-crystal and the physical mixture of its component crystals. Because the two melting processes arrive at the same liquid, the difference of their enthalpy changes is the co-crystal's formation enthalpy. For the system of nicotinamide (NIC) and R-mandelic acid (RMA), the formation enthalpy at 30 degrees C is -23 (3) J/g for polymorph 1 and -18 (3) J/g for polymorph 2. These values are comparable with the enthalpy of mixing for NIC and RMA liquids [-49 (4) J/g at 160 degrees C], indicating the need for correcting for nonideal mixing in calculating formation enthalpies of co-crystals via thermodynamic cycles. This correction is made automatically in our method by performing measurements with physical mixtures of component crystals, as opposed to pure component crystals. One of the NIC-RMA polymorphs (2) was discovered in this work, and its structure and thermodynamic relation to polymorph 1 are reported.

  DOI：

  10.1021/cg3005757

文献信息

• Cocrystals of Nicotinamide and (<i>R</i>)-Mandelic Acid in Many Ratios with Anomalous Formation Properties
  作者：Si-Wei Zhang、Michelle T. Harasimowicz、Melgardt M. de Villiers、Lian Yu

  DOI：10.1021/ja4103887

  日期：2013.12.18

  We report a remarkable system of cocrystals containing nicotinamide (NIC) and (R)-mandelic acid (RMA) in numerous stoichiometric ratios (4:1, 1:1 in two polymorphs, and 1:2) with anomalous formation properties. The formation of these cocrystals decreases energy but expands volume, in contrast to most physical processes, but similar to water freezing. The decrease of energy upon cocrystallization agrees with the exothermic mixing of NIC and RMA liquids (a base and an acid). Volume expansion is general for the formation of all NIC cocrystals for which data exist (n = 40): +3.9 angstrom(3)/molecule or +17 cm(3)/kg on average, corresponding to a 2% expansion. This volume expansion correlates with the shortening and strengthening of hydrogen bonds upon cocrystallization, analogous to water freezing. The NIC-RMA binary phase diagram was constructed that contains the congruent and incongruent melting of six crystalline phases. These results are relevant for understanding the nature of cocrystallization and why some molecules are prolific cocrystal formers.