George A. Neville

Fourier transform Raman and infrared study of nitrazepam, nimetazepam, clonazepam and flunitrazepam

Abstract Fourier transform Raman and infrared spectra of four compounds closely related to diazepam (Valium) were recorded in the solid state, namely nitrazepam, nimetazepam, clonazepam and flunitrazepam, all of which have a nitro group at position 7 in the 1,4-benzodiazepine structure. The spectra show characteristic features associated with both the diazepine ring and substituents. The Raman and infrared spectra all have a very strong band near 1340 cm−1, which is assigned to the symmetric stretching mode of the NO2 group. A strong line near 1610 cm−1 in the Raman spectra is assigned to the C = N stretch of the diazepine ring and the very strong IR absorption near 1690 cm−1 is attributed to the C=O stretching mode. Evidence for intermolecular hydrogen bonding in nitrazepam and clonazepam is presented.

Thermal analyses (TGA and DSC) of some spironolactone solvates

Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) studies have been performed on a commercial preparation of spironolactone and on five solvates (acetonitrile, ethyl acetate, ethanol, methanol, and benzene) prepared from it by recrystallization at room temperature. The results of these studies are discussed and compared with those recently reported in the literature for similar preparations. The variable behaviour of these solvates in their release (and partial retention) of solvent before the onset of melting, meant that their stoichiometry had to be measured by elemental microanalyses. Solvent loss from solvate decomposition was followed by thermogravimetric analysis (TGA). Solvate decomposition and spironolactone melting temperatures and enthalpies were determined by differential scanning calorimetry (DSC). The parent substance and two of the solvates (methanol and ethanol) exhibited small exotherms in addition to the expected endotherms.

Differentiation of solvated spironolactone samples by FT-Raman and FT-IR diffuse reflectance spectroscopy

SummaryFive solvates of spironolactone were prepared by crystallization from absolute methanol, acetonitrile, absolute ethanol, ethyl acetate, and benzene, and characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and by FT-Raman spectroscopy. Of these solvates, all were found to be monosolvated except that formed with acetonitrile which gave a spironolactone-acetonitrile (2:1) complex as determined by elemental microanalysis. Distinctive IR and Raman spectral features of the solvates are discussed. Remarkable similarity is seen in the Raman spectra (1800–400 cm−1) of the solvates obtained from methanol, ethanol, and ethyl acetate. The Raman spectrum of the benzene solvate is particularly useful for showing the presence of benzene because of the very intense band near 1000 cm−1 which is unique to the Raman effect.

Fourier Transform Infrared/Raman Differentiation and Characterization of Cis - and Trans -2,5-Dimethoxy-4,β-Dimethyl-β'-Nitrostyrenes: Precursors to the Street Drug STP

Fourier transform Raman and infrared spectra of pure cis(Z)- and trans(E)-2,5-dimethoxy-4,beta-dimethyl-beta-nitrostyrene (precursors of the psychotomimetic street drug STP or DOM) were recorded in the solid state. The spectra show characteristic features of the ethylene moiety and of the aryl and nitro substituents which permit ready differentiation and identification of these isomers. A very strong Raman line at 1670 cm-1 from the cis isomer for the C=C stretching mode, in comparison with a strong Raman line at 1641 cm-1 for the trans isomer, affords primary differentiation of these substances. A second characteristic, of both the Raman and infrared (IR) spectra, is that the frequency of the strong symmetric nitro (NO2) stretching band is about 40 cm-1 higher in the cis (1346 cm-1) than the trans isomer (1301 cm-1). All major IR and Raman bands are reported and given vibrational assignments.

Synthesis and Spectral Properties of 2,5-Dimethoxy-4-Ethoxyamphetamine and Its Precursors

2,5-Dimethoxy-4-ethoxyamphetamine (MEM) was synthesized by two routes. The gas liquid chromatographic data and ultraviolet, infrared, proton magnetic resonance, carbon-13 magnetic resonance, and mass spectra are presented for this amphetamine as well as its precursors. This amphetamine was found to be identical to the sample submitted by the police.

Identification of Two New “Designer” Amphetamines by NMR Techniques

ABSTRACTTwo new designer amphetamines (4-chloro-2, 5-dimethoxyamphetamine and 2, 5-dimethoxy-4-methylthioamphetamine) were identified by nuclear magnetic resonance (NMR) techniques. Nuclear Overhauser Effect (NOE) difference spectra provided all the necessary structural information to identify the unknowns. Lanthanide shift reagent (LSR) studies provided an alternate method to prove positional substitution for the structures.

Fourier Transform-Infrared (FT-IR) Characterization of the Ethyl Acetate Complex of O6-Acetylmorphine

The solid-state infrared spectral features of the (1:1) O6-acetylmorphine-ethyl acetate complex are compared to those of its host, O6-acetylmorphine base, and to its very similar analog, O3,O6-diacetylmorphine (heroin). The formation of a stable complex appears to be unique to O6-acetylmorphine for neither morphine nor its closely related derivatives, codeine, thebaine, heroin, or O3-acetylmorphine form isolable adducts during ethyl acetate extraction. Factors affecting formation of this complex during workup and extraction of forensic science exhibits are discussed.

A Direct Synthesis of O6-Monoacetylmorphine from Morphine

ABSTRACTO6-Monoacetylmorphine was synthesized directly in good yield from morphine with glacial acetic acid using sulphuric acid as a catalyst. The product was characterized by PMR, IR, MS, and elemental microanalysis. This successful synthesis of O6-monoacetylmorphine from morphine shows that this compound can be included under the Narcotic Control Act as a regulated substance for legal purposes.

Spectral Identification of a Lachrymatory Exhibit as CS

ABSTRACTAn unknown, lachrymatory solid was identified as 2-chlorobenzylidene malononitrile, otherwise known as CS, by means of IR, MS, 1H-and 13C-NMR spectra. Given the difficulty in obtaining either reference spectra or reference samples of benzylidene malononitriles (BMNs)—because of the classified nature and use of such substances in numerous anti-personnel and riot control devices—reported spectra serve to fulfil a forensic analytical need.

Mercury(II) Complexes of L-Cysteine Methyl Ester

The mercurial complexation of L-cysteine methyl ester hydrochloride with mercury(II) nitrate, chloride, and acetate has been investigated at low pH. Bis(methyl L-cysteineato)mercury(II) hydrochloride hydronitrate monohydrate, following isolation and extensive characterization, was shown to be the substance reported in the literature as the dihydrochloride sesquihydrate complex. The preparation and properties of bis(methyl L-cysteineato)mercury(II) dihydrochloride monohydrate are reported for the first time. The properties and structural features of the complexes are discussed mainly in the context of investigations utilizing infrared, 1H- and 13C-n.m.r. spectroscopy.