Crystal structure and conformation of the antimalarial drug 5,7-methoxy-8-(3-methyl-1-buten-3-ol)-coumarin
Source: Journal of Chemical Crystallography, Volume 33, Number 2, February 2003 , pp. 149-153(5)
The crystal and molecular structure of the antimalarial compound 5,7-methoxy-8-(3-methyl-1-buten-3-ol)-coumarin, C16H18O5, Mr = 290.3 Da, has been determined from X-ray diffraction data. The material crystallizes in the monoclinic space group P21/c with 4 molecules per unit cell of dimensions a = 8.9044(9), b = 17.623(1), c = 10.175(1) Å, = 113.97(1)°, crystal density Dc = 1.322 g/cm3. The structure was determined using direct methods and refined by full-matrix least squares to a conventional R index of 0.066 for 2416 measured reflections and 206 parameters.The coumarin ring system is almost planar with the methoxy C atoms rotated slightly out of the coumarin mean plane. Apart from the terminal CH3 groups C(12) and C(13), which are 1.184(3) Å above and -1.315(3) Å below the plane, the 3-methyl-1-buten-3-ol substituent is planar (rms deviation 0.009 Å) making an angle of 6.31(7)° with the phenyl ring. One intermolecular hydrogen bond is present in the crystal structure between O(5)HO(5) and the symmetry related O(2) oxygen, generated by the symmetry operation (x, 1/2 y, -1/2 + z).
Document Type: Research article
Affiliations: 1: Department of Crystallography, Birkbeck College, University of London, London, United Kingdom 2: Institut de Biologia Molecular de Barcelona, CSIC, Barcelona, Spain 3: Department of Pharmacology and Faculty of Pharmacy, College of Health, University of Nairobi, Nairobi, Kenya 4: Department of Crystallography, Birkbeck College, University of London, London, United Kingdom; firstname.lastname@example.org
Publication date: 2003-02-01