Schmidt, A. C. published the artcileCrystal polymorphism of local anesthetic drugs. Part I: Pramocaine base in comparison with pramocaine hydrochloride, Application In Synthesis of 637-58-1, the publication is Journal of Thermal Analysis and Calorimetry (2003), 73(2), 397-408, database is CAplus.
Crystal polymorphs of pramocaine hydrochloride (PRCNC) and pramocaine (PRCN) free base were produced and characterized by means of thermomicroscopy, differential scanning calorimetry (DSC), FTIR- and FT-Raman-spectroscopy as well as x-ray-powder diffractometry. The relative thermodn. stabilities of all forms were determined and are represented in semi-schematic energy/temperature diagrams. PRCN, which is a viscous liquid at room temperature and insoluble in water, was found to exist in two different crystal forms with the m.ps. 23.5° (mod. I°) and 12.5° (mod. II). The water-soluble PRCNC crystallizes in three different crystal modifications. Mod. II° is the thermodynamically stable form at room temperature and is present in com. products. This form is obtained by crystallization from solvents and transforms on heating at about 95° into the high temperature form mod. I which melts at 171.0°. Both compounds show conformational polymorphism with forms of low kinetic stability.
Journal of Thermal Analysis and Calorimetry published new progress about 637-58-1. 637-58-1 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is 4-(3-(4-Butoxyphenoxy)propyl)morpholine hydrochloride, and the molecular formula is C17H28ClNO3, Application In Synthesis of 637-58-1.
Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem