Bis((S)-5,5-dimethylthiazolidine-4-carboxylic acid) protium chloride hydrate [(C6H11NO2S)2H]Cl•H2O, a salt containing a hemi-protonated zwitterion

1987 ◽  
Vol 65 (4) ◽  
pp. 878-883 ◽  
Author(s):  
H. E. Howard-Lock ◽  
C. J. L. Lock ◽  
M. L. Martins ◽  
R. Faggiani ◽  
M. Duarte

The X-ray crystal structure of bis((S)-5,5-dimethylthiazolidine-4-carboxylic acid) protium chloride hydrate, I, has been determined. Crystals are orthorhombic, P212121, with cell dimensions a = 6.463(2), b = 11.832(3), c = 23.966(6) Å, and Z = 4. The structure was solved by standard methods and refined to R = 0.073, Rw = 0.064 for 2969 independent reflections. Compound I is composed of two zwitterion molecules bridged through a proton which causes a very short hydrogen bond, O … O′ = 2.450 Å. The proton is located roughly halfway between the two carboxylate oxygen atoms, but is not on a special crystallographic position. Characteristic features of the infrared and Raman spectra, mass spectra, and 1H and 13C nmr spectra are discussed.

1985 ◽  
Vol 63 (9) ◽  
pp. 2411-2419 ◽  
Author(s):  
Helen Elaine Howard-Lock ◽  
Colin James Lyne Lock ◽  
Philip Stuart Smalley

The X-ray crystal structure of (S)-2,2,5,5-tetramethylthiazolidine-4-carboxylic acid, 1, has been determined. Crystals are monoclinic, P21, with cell dimensions a = 11.351(4) b = 8.303(2), c = 11.969(3) Å, β = 116.69(2)°, and Z = 4. The structure was solved by standard methods and refined to R1 = 0.0774, R2 = 0.0670 for 2388 independent reflections. Compound 1 exists in the amino-acid form as shown by two distinctly different C—O bond lengths, 1.209 and 1.309 Å, typical of the COOH group, and by the positions of the hydrogen atoms. The amino-acid form of 1 found in the solid also exists in solution as shown by infrared and Raman spectra. The mass spectra, and 1H and 13C nmr spectra are reported, as well as detailed infrared and Raman spectra for the title compound and several deuterated species.


1983 ◽  
Vol 48 (12) ◽  
pp. 3426-3432 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Ondrej Forgáč

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.


1980 ◽  
Vol 45 (2) ◽  
pp. 548-558 ◽  
Author(s):  
Antonín Klásek ◽  
Petr Sedmera ◽  
Jindřich Vokoun ◽  
Anna Boeva ◽  
Svatava Dvoráčková ◽  
...  
Keyword(s):  
H Nmr ◽  

From S. nemorensis L., var. subdecurrens GRISEB. there were isolated the previously obtained alkaloids nemorensine (I), retroisosenine (II), bulgarsenine (III) and, in addition, the alkaloid oxynemorensine which was assigned the structure VIII on the basis of the interpretation of the 1H-NMR, 13C-NMR, mass spectra, and on that of the identification of the products of hydrolysis and reduction. Furthermore, the isolation of the cis-nemorensic acid (V) as well as that of the unsaturated acid IV, and the transformation of bulgarsenine (III) to nemorensine (I) were described.


1987 ◽  
Vol 65 (2) ◽  
pp. 261-270 ◽  
Author(s):  
R. A. Bell ◽  
B. E. Brown ◽  
M. Duarte ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock

1,1,3,3-Tetracyanopropane, 1, was prepared in low yields by a literature method with 2,2,4,4,6-pentacyanocyclohexenamine, 2, as a major by-product. The products were examined by X-ray crystallography. 1 has an orthorhombic space group, Pbcn (No. 60) with cell dimensions, a = 7.158(2), b = 10.510(3), c = 9.733(2) Å and has four formula units in the unit cell. 2 has a monoclinic cell, P21/c (No. 14) with cell dimensions a = 14.368(3), b = 6.626(1), c = 12.300(2) Å, β = 115.60(1)° and has 4 formula units in the unit cell. Data were collected with use of MoKα radiation and a Nicolet P3 diffractometer. The crystal structures were determined by standard methods and refined to Rw = 0.037 (1) and Rw = 0.040 (2) on the basis of 782 and 2108 unique reflections. Bond lengths and angles in the two compounds are normal. 2 has what has been considered to be the less likely tautomeric structure. Both compounds were examined by 1H, 13C nmr, vibrational spectroscopy, and mass spectroscopy. For 2 there was no evidence of the alternative tautomeric structure. New methods were developed for the preparation of both compounds and the mechanism of the original reaction rationalized.


2019 ◽  
Vol 138 (4) ◽  
pp. 2813-2837 ◽  
Author(s):  
G. Świderski ◽  
R. Świsłocka ◽  
R. Łyszczek ◽  
S. Wojtulewski ◽  
M. Samsonowicz ◽  
...  

Abstract The new 3d metal complexes of pyrimidine-2-carboxylic (2PCA) and pyrimidine-5-carboxylic (5PCA) acids were synthesized and characterized using thermal analysis (TG–DSC, TG–FTIR), X-ray, spectroscopic (IR, Raman) methods and theoretical (DFT) studies. In the complexes of pyrimidine-2-carboxylic acid of the general formula M(2PCA)2·xH2O (where 2PCA-pyrimidine-2-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 0 for Mn and Cu; x = 2 for Co, Ni and Zn) coordination of metal ions occurs through nitrogen atom from pyrimidine ring and carboxylate oxygen atom. The complexes of pyrimidine-5-carboxylic acid of the general formula M(5PCA)2·xH2O (where 5PCA—pyrimidine-5-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 6 for Cu and 4 for remaining complexes) were obtained as monomeric isostructural compounds. Coordination of metal centers occurs through two nitrogen atom from different pyrimidine-5-carboxylate ligand and four oxygen atoms from water molecules. The IR and Raman spectra of free acids as well as obtained metal(II) complexes were described in detail. Aromaticity (HOMA, EN, GEO and I6) of complexes was determined and discussed. The investigated compounds decompose in air in two main stages connected with dehydration and decomposition/burning of anhydrous compounds to the suitable metal oxides. Thermal decomposition in nitrogen leads to the evolution of water, carbon oxides, ammonia and pyrimidine molecules.


1965 ◽  
Vol 20 (7) ◽  
pp. 883-887 ◽  
Author(s):  
J. H. Beynon ◽  
B. E. Job ◽  
A. E. Williams

The mass spectra of benzoic acid, phthalic acid, isophthalic acid and terephthalic acid, together with the analogues deuterated on the carboxylic acid group have been studied. Exchange of the deuterium atom with hydrogen atoms on the positions ortho to a carboxylic acid group on the aromatic ring has been studied using meta-stable peaks.


2020 ◽  
pp. 174751982093226
Author(s):  
Öznur Şener Cemaloğlu ◽  
Hatice Ogutcu ◽  
Zeliha Hayvalı

New aldehyde- and halogen- (Cl, Br, I) substituted double-armed benzo-15-crown-5 derivatives are synthesized by the reactions of 4′,5′-bis(bromomethyl)benzo-15-crown-5 with 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, or 5-iodosalicylaldehyde. The sodium and potassium complexes are obtained by reaction of crown ether with sodium perchlorate and potassium iodide, respectively. Novel Schiff base compounds containing three groups of benzo-15-crown-5 are obtained from the condensation of aldehydes with 4′-aminobenzo-15-crown-5. The structures of all compounds are elucidated by elemental analysis, 1H, 13C NMR, IR, and mass spectra. The antifungal and antibacterial effects of the synthesized ligands are evaluated against pathogenic microorganisms and show varying degrees of inhibitory effects against the growth of different pathogenic strains. Graphical abstract


2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Virginia F. Rodrigues ◽  
Rodrigo R. Oliveira ◽  
Maria Raquel G. Vega

A new isocoumarin, 3-phenyl-8-hydroxy-6-methoxy-5-γ, γ-dimethylallyl-isocoumarin, named cajavilmina (1) and eight known compounds: α-amirenone (2), β-amirenone (3), lupenone (4), 5-hydroxy-7-methoxydihydroflavone (5), longistilin C (6), 3-hydroxy-5-methoxystilbene (7), β-sitosterol (8) and stigmasterol (9) were identified in a dichloromethane fraction from Cajanus cajan leaves. Structures were elucidated by analysis of spectral data, mainly those afforded by 1H, NOEDIFF and 13C NMR (1D and 2D NMR HMQC, HMBC and COSY) and mass spectra.


1986 ◽  
Vol 41 (2) ◽  
pp. 144-148 ◽  
Author(s):  
Max Herberhold ◽  
Wolfgang Jellen

The first seleninylamine, tBuNSeO, was prepared from tert-butylamine, tBuNH2, and SeOCl2 (3:1). The selenium diimide Se(NBut)2 was isolated from the corresponding reaction of tBuNH2 and SeCl4 (6:1); it decomposes at ambient temperature to give cyclic Se3(NBut)2. The new compounds were characterized on the basis of their IR , 1H and 13C NMR and mass spectra.


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