A New Crystal Structure of Clarithromycin

Abstract A new crystal structure of clarithromycin single acetonitrile solvate designated “Form III” was first determined by single crystal X-ray diffraction. The compound crystallized in the monoclinic system, P2 ₁ space group with a = 10.644(2) ?, b = 18.099(4) ?, c = 11.628(2) ?, α = γ = 90°, β = 95.38(3)°, V = 2230.1(8) ?³, Z = 2, D _c = 1.175 g/cm³, μ = 0.087 mm⁻¹, F(000) = 860, R ₁ = 0.034, wR ₂ = 0.062, S = 0.875, (Δ/σ)_max = 0.001 for 2,709 observed reflections (I > 2σ (Ι)). Form III of clarithromycin, contrary to Form I, is more thermodynamically stable than Form II used currently on the market. Graphical abstract A New Crystal Structure of Clarithromycin Jian-Hua Liang, Guo-Wei Yao A crystal structure of clarithromycin single acetonitrile solvate was first determined by single crystal X-ray diffraction.