Crystal structure of 4-propyl-3-methyl-1-phenyl-2-pyrazolin-5-one thiosemicarbazone, C15H19N5OS

Abstract

Source of materialAnalyticalgrade reagents as procured were used without further purification.T oasolution of synthesized4-propyl-3-methyl-1-phenyl-2-pyrazolin-5-one (2.0 mmol, 0.52 g) in methanol (10 mL)was added slowly thiosemicarbazide (2.0 mmol, 0.18 g) in methanol (10 mL) while stirring and the golden brown mixture obtained was refluxed for 3h.The yellow precipitate was filtered, washed with methanol, dried at room temperature and stored over fused CaCl 2 .Yellow single crystals of the title keto imine Schiff base suitable for x-ray diffraction were grown at room temperature from slow evaporation of dimethylformamide solution. Experimental detailsCarbon-bound Hatomswere placed in calculated positions and were included in the refinement in the riding model approximation, with U iso (H) set to 1.2 U eq (C). The Hatoms of the methyl groups were allowed to rotate with afixed angle around the C-C bond to best fit the experimental electron density (HFIX 137 in the SHELX program suite [8]), with U iso (H) setto1.5U eq (C). The nitrogen-bound Ha tomsw ere located on ad ifference Fourier mapand refined freely. DiscussionDi-ketone acylpyrazolone are good biological, catalytic and analyticalreagents, as such they have been widely used [1]. They can chelate metal ions, aproperty that have been reported to increase their efficiency [2]. They form useful Schiffb ases with amino groups [3,4 ]. Thiosemicarbazides are an interesting group of compounds with versatile properties. They are good chelating reagents which form superior tridentate Schiff bases with ONS coordination sites with metal ions [5]. Acylpyrazolone with benzoyl derivative have been used for the synthesis of Schiff bases and have been reported by us earlier [3,4 ]. Presented herein is the crystal and molecular structure of a4-propyl-3-methyl-1-phenyl-2-pyrazolin-5-one Schiff base with thiosemicarbazide. In this crystal structure one molecule is present in the asymmetricunit. Thebackboneofthe structureisessentially planar indicatingan amidetyperesonance.The least-square planethrough thebackbone atoms N1-N3, C1-C3, C5 and O1 has ar.m.s. deviation of only 0.0049 Å. The intramolecular hydrogen bond N3-H3×××O1 of length 1.904(17) Åa lso helps to maintain planarity. The C11-C16 phenyl ring is rotated outofthe abovementioned plane with its least square plane making adihedralangle of 25.82(6)°w ith the main plane.T he phenylr ingh as an intramolecular C12-H12×××O1 hydrogen bond of length 2.44 Å. Thereare anumber of intermolecular hydrogen interactions forming infinite chains in the structure. The N4-H4×××S1 bond has al ength of 2.482(17) Åand in terms of Graph Set analyses [6,7]forms a chain along the b-axisthatcan be describedbyaC 1 1 (4) descriptor on the unary level. TheN5-H5B×××N2 interaction of 2.154(16) Å also formsachain along the b-axis and has adescriptor of C 1 1 (9) on the unary level. Thesum of the aforementioned classical hydrogen bonds lead to alayered structure (parallel to the ab plane).

Spectroscopy, Crystal and Molecular Structures of New 4-Acylpyrazolone Dinitrophenylhydrazones

“…Our work on the development of new Schiff bases with novel properties [15,16], taking advantage of functional group modifications, continues in this paper. The single-crystal structure of 4-ethyl and 4-propyl pyrazolone derivatives of 2,4-dinitrophenylhydrazones alongside their spectroscopic properties are presented and discussed.…”

“…We have synthesized a benzoyl derivative of a 2,4-dinitrophenylhydrazone with a solvent molecule distortion, titled, 4-{[2-(2,4-Dinitrophenyl)hydrazinylidene]-(phenyl)methyl}-5-methyl-2-phenyl-1H-pyrazol-3-(2H)-one ethanol monosolvate [13], as well as a group of other benzoyl derivatives of 4-acylpyrazolone Schiff bases which have shown interesting biological properties both as ligands and as transition metal complexes [14]. Our work on the development of new Schiff bases with novel properties [15,16], taking advantage of functional group modifications, continues in this paper. The single-crystal structure of 4-ethyl and 4-propyl pyrazolone derivatives of 2,4-dinitrophenylhydrazones alongside their spectroscopic properties are presented and discussed.…”

Crystal structure of bis(N′-((1H-pyrrol-2-yl)methylene)-1-methylthio-methanethiohydrazido-κ2 S,N)nickel(II), C14H16N6NiS4

“…In the crystal, there exist intromolecular N-H· · · N hydrogen bonds between the pyrrole N and uncoordinated hydrazone N atoms. All geometric parameters of the methylthiomethanethiohydrazone ligand are in the expected ranges [7].…”

Crystal structure of (E)-2-(2-chloro-6-hydroxybenzylidene)hydrazine-1-carbothioamide, C8H8ClN3O4S

“…Thiosemicarbazones are a class of important Schiff-bases and have received considerable attention for many years because of their biological activities and coordination chemistry properties [3][4][5][6][7][8][9][10][11][12][13][14]. In order to search for new thiosemicarbazones, the title compound was synthesized and its crystal structure was determined.…”