Original scientific paper

Chemistry of Torasemide. Molecular and Crystal Structure of New Polymorph N

Aleksandar Danilovski ; PLIVA d. d., Research and Development, Prilaz baruna Filipovića 25, HR-10000 Zagreb, Croatia
Darko Filić ; PLIVA d. d., Research and Development, Prilaz baruna Filipovića 25, HR-10000 Zagreb, Croatia
Marina Orešić ; PLIVA d. d., Research and Development, Prilaz baruna Filipovića 25, HR-10000 Zagreb, Croatia
Miljenko Dumić ; PLIVA d. d., Research and Development, Prilaz baruna Filipovića 25, HR-10000 Zagreb, Croatia

Abstract

It is known from literature that torasemide, generic name for N1-isopropyl-N3-[4-(3-methylphenylamino)-3-pyridylsulphonyl]urea, can have two polymorphic forms, denoted as T-I and T-II. A novel, third polymorph N of torasemide, T-N has been discovered and fully characterised. It crystallises in the centrosymmetric monoclinic space group P2₁/c with two crystallographically independent molecules, which differ primarily in their different phenyl ring and A1-isopropyl side chain orientations. Both independent molecules, i.e. conformations, can adopt a zwitter-ionic structure. The new polymorph of torasemide is characterised by a considerably complex three-dimensional hydrogen-bonding network that spans ali over the crystal unit cell. The crystal packing of T-N is rather crowded, dense and compact. It is pointed out that the degree of crystal structure diversity of the existing torasemide polymorphs is considerably high, with different conformational properties of distinct torasemide molecules in its asymmetric unit.

Keywords

torasemide; pyridylsulphonylurea; polymorphism; X-ray diffraction; conformation

Hrčak ID:

131779

URI

https://hrcak.srce.hr/131779

Publication date:

1.2.2001.

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