Tetraphenylborate Salt of Atropine®: Synthesis and X-ray Structure of Tetraphenyl-λ4-borane, (1R,3r,5S,8s)-3-((3-Hydroxy-2-phenylpropanoyl)oxy)-8-methyl-8-azabicyclo[3.2.1]octan-8-ium Salt

Abstract

The title compound, tetraphenylborate salt of atropine (RS)-(8-Methyl-8-azabicyclo[3.2.1]oct-3-yl) 3-hydroxy-2-phenylpropanoate tetraphenylborate salt, was prepared by the reaction of (RS)-(8-Methyl-8-azabicyclo[3.2.1]oct-3-yl) 3-hydroxy-2-phenylpropanoate sulfate (2:1) salt with sodium tetraphenylborate in deionized water at ambient temperature through anion exchange reaction. Colorless crystals of the title compound suitable for X-ray structural analysis were obtained by slow evaporation from acetonitrile. The title compound crystallizes in the triclinic sp. gr. P1 with a = 9.7989(5) Å, b = 9.8203(5) Å, c = 18.6099(9) Å, α = 81.356(2)°, β = 80.616(2)°, γ = 67.704(2)°, V = 1627.05(14) ų, Z = 2.