The N-alkylation of some barbiturates and other acidic drugs

1976 ◽  
Vol 29 (8) ◽  
pp. 1769 ◽  
Author(s):  
S Dilli ◽  
DN Pillai
Keyword(s):  
Anticonvulsant Drugs ◽  
Chromatographic Retention ◽  
Retention Data ◽  
Mass Spectral ◽  
Acidic Drugs ◽  
Derivatives Of

The synthesis of a number of new N,N'-dialkyl barbituric acids is reported. The compounds are ethyl hexobarbital, the diethyl derivatives of secobarbital and cyclobarbital, the chloroethyl derivatives ofmephobarbital and hexobarbital, and the bis(chloroethy1) derivatives of barbital, cyclobarbital, secobarbital, butobarbital and secbutobarbital.In addition, several new N-alkylated derivatives of some common anticonvulsant drugs are included. These are ethyl glutethimide, the chloroethyl derivatives of ethosuximide, glutethimide, peganone, mephenytoin and diphenylhydantoin. Infrared, N.M.R., mass spectral and gas chromatographic retention data are given.

scholarly journals The separation and sequencing of permethylated peptides by mass spectrometry directly coupled to gas-liquid chromatography

1976 ◽  
Vol 157 (3) ◽  
pp. 777-780 ◽  
Author(s):  
J D Priddle ◽  
K Rose ◽  
R E Offord
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Chemical Ionization ◽  
Chromatographic Retention ◽  
Gas Liquid Chromatography ◽  
Retention Data ◽  
Primary Sequence ◽  
Peptide Derivatives ◽  
Derivatives Of

The use of g.l.c. coupled to mass spectrometry to separate and sequence permethylated acetyl- and trifluoroacetyl-peptides in a single operation is described. Both electron impact and chemical ionization were used to induce fragmentation, and the latter was found to be more sensitive. Chromatographic retention data are presented which suggest that peptide derivatives of molecular weight of at least 750 are accessible to the technique. The application of our methods to the determination of the primary sequence of proteins is discussed.

Detection of O,O-Diethyl-O-(2,5-dichlorophenyl) Phosphorothioate and O,O-Diethyl-O-(3,6-dichloro-2-pyridyl) Phosphorothioate in Meat Fat

1976 ◽  
Vol 59 (5) ◽  
pp. 1081-1087
Author(s):  
Barry G Luke ◽  
Colin J Dahl
Keyword(s):  
The Other ◽  
Chromatographic Retention ◽  
Retention Data ◽  
Mass Spectral ◽  
Spectral Evidence ◽  
Liquid Chromatographic

Abstract Two previously unreported organophosphorus residues have been detected in meat fat. The first, O,O-diethyl-O-(2,5-dichlorophenyl) phosphorothioate, apparently results from the debromination of bromophos-ethyl, while the other, O,O-diethyl-O-(3,6-dicliloro-2-pyridyl) phosphorothioate, presumably arises by the monodechlorination of chlorpyriphos. Mass spectral evidence is presented in support of the assigned structures and gas-liquid chromatographic retention data for the residues and their oxygen analogs are provided.

Synthesis and Identification of ω-Phenylalkylcatechols in Burmese Lac

1988 ◽  
Vol 41 (1) ◽  
pp. 19 ◽  
Author(s):  
A Jefferson ◽  
MV Sargent ◽  
S Wangchareontrakul
Keyword(s):  
Natural Products ◽  
Catalytic Hydrogenation ◽  
Wittig Reaction ◽  
Spectral Characteristics ◽  
Chromatographic Retention ◽  
Phosphonium Bromide ◽  
Mass Spectral ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of

The presence of 3-(10′-phenyldecyl)-(2) (2%), 3-(12′-phenyldodecyl)- (3) (6%), 4-(10′-phenyldecyl)-(4) (0.3%) and 4-(12′-phenyldodecyl)- benzene-1,2-diol (5) (0.3%) in Burmese lac , the sap of Melanorrhoea usitata Wall has been confirmed by the synthesis of these compounds and a comparison of the gas chromatographic retention times and the mass spectral characteristics of their bis-O-( trimethylsilyl ) derivatives with the derivatives of the natural products. Typically, 3,4- bis ( benzyloxy ) benzaldehyde (7) on Wittig reaction with triphenyl (11- phenylundecyl ) phosphonium bromide (20) and subsequent catalytic hydrogenation of the resultant olefin gave compound (5) in 59% overall yield.

Gas chromatographic retention data for silyl and acyl derivatives of nucleosides

1980 ◽  
Vol 196 (3) ◽  
pp. 367-378 ◽  
Author(s):  
Michael A. Quilliam ◽  
Kelvin K. Ogilvie ◽  
Krishan L. Sadana ◽  
John B. Westmore
Keyword(s):  
Chromatographic Retention ◽  
Retention Data ◽  
Derivatives Of ◽  
Acyl Derivatives

Microwave-induced rapid preparation of fluoro-derivatives of amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine for GC-MS confirmation assays

1994 ◽  
Vol 40 (9) ◽  
pp. 1703-1706 ◽  
Author(s):  
W C Thompson ◽  
A Dasgupta
Keyword(s):  
Microwave Irradiation ◽  
Conventional Technique ◽  
Conventional Heating ◽  
Chromatographic Retention ◽  
Rapid Preparation ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Fragmentation Patterns ◽  
Derivatives Of ◽  
Fluoro Derivatives

Abstract We prepared trifluoroacetyl, pentafluoropropyl, and heptafluorobutyl derivatives of amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA) in 45 s, 1 min, and 6 min, respectively, by using microwave irradiation. Conventional techniques require heating the reaction mixture for 15 min at 40 degrees C for trifluoroacetyl derivatives, 15 min at 75 degrees C for pentafluoropropyl derivatives, and 40 min at 60 degrees C for heptafluorobutyl derivatives. The mass-spectral fragmentation patterns and the gas-chromatographic retention times of the derivatives obtained by both microwave irradiation and conventional heating were similar. Perfluorooctanoyl derivatives of amphetamine can be prepared quantitatively by either heating the reaction mixture for 30 min at 60 degrees C or by 1 min of microwave irradiation. Conversion of methamphetamine and MDMA to the corresponding perfluorooctanoyl derivatives was not quantitative by either technique, although the yield of the derivative in the conventional technique was much higher.

scholarly journals Interaction of Fullerenes with Organosilanes in the Ionization Chamber of a Mass Spectrometer under Electron Impact and the Reaction of C60with Tetraphenylsilane in Solution under UV Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Yury I. Lyakhovetsky ◽  
Elena A. Shilova ◽  
Alexandra P. Pleshkova ◽  
Alexander I. Belokon ◽  
Sergey O. Yakushin ◽  
...  
Keyword(s):  
Electron Impact ◽  
Mass Spectrometer ◽  
Uv Irradiation ◽  
Ionization Chamber ◽  
Ion Source ◽  
Organic Radicals ◽  
Mechanistic Study ◽  
Mass Spectral ◽  
Additional Support ◽  
Derivatives Of

C60was shown to react with organosilanes Me4Si, Ph2SiH2, Ph2MeSiH, Ph4Si, andα-naphthylphenylmethylsilane in the electron ionization ion source of a mass spectrometer with the transfer of the corresponding organic radicals (Me, Ph, andα-naphthyl) from the silanes to the fullerene. The reactions were accompanied by hydrogen addition to some products and hydrogen loss from them. C70reacted with Me4Si analogously. A reaction mechanism involving homolytic dissociation of the silanes under electron impact to the corresponding organic radicals, which react further with C60at the surface of the ionization chamber of the mass spectrometer to give the respective adducts, was offered. A mechanistic study of the reaction of C60with Me4Si supported it. No silicon containing derivatives of the fullerenes were found. C60reacted with Ph4Si in solution under UV irradiation in a similar fashion furnishing phenyl derivatives of the fullerene. These results provide an additional support to the hypothesis formulated earlier thatthe homolytic reactive mass spectrometry of fullerenes (the reactions of fullerenes with other species in the ionization chambers of mass spectrometers and their mass spectral monitoring)can predict the reactivity of them toward the same reagents in solution to a significant extent.

scholarly journals Gas-Liquid Chromatographic Retention Data for Some isoThiocyanates.

1961 ◽  
Vol 15 ◽  
pp. 1223-1230 ◽  
Author(s):  
Aage Jart ◽  
Knud Engel ◽  
Robert Nilsson ◽  
Gert E. Olsen ◽  
Christian Pedersen ◽  
...  
Keyword(s):  
Chromatographic Retention ◽  
Retention Data ◽  
Liquid Chromatographic

Massenspektrometrische Fragmentierung von Trimethylsilylderivaten (TMS) des Thyrotropin-„Releasing“-Hormons (TRH) und dessen Teilstrukturen / Mass Spectroscopy of Trimethylsilyl Derivatives of Thyrotropin-releasing Hormone and its Constituents

1973 ◽  
Vol 28 (11-12) ◽  
pp. 820-823 ◽  
Author(s):  
W. A. König ◽  
S. Fuchs ◽  
K. Zech ◽  
W. Voelter
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectroscopy ◽  
Peptide Hormones ◽  
Thyrotropin Releasing Hormone ◽  
Mass Spectral Fragmentation ◽  
Releasing Hormone ◽  
Mass Spectral ◽  
Trimethylsilyl Derivatives ◽  
Fragmentation Patterns ◽  
Derivatives Of

The mass spectral fragmentation patterns of trimethylsilyl derivatives of TRH and its constituents are discussed. The utility of these derivatives for the control of the synthesis of peptide hormones by mass spectrometry is obvious.

Preparation and Spectroscopic Characterisation of a Series of Heterobimetallic N-phenyldiethanolaminate-alkoxide Derivatives of Oxovanadium(V)

2005 ◽  
Vol 2005 (6) ◽  
pp. 352-355 ◽  
Author(s):  
Rajendra Singh Ghadwal ◽  
Ram C. Mehrotra ◽  
Anirudh Singh
Keyword(s):  
Molecular Weight ◽  
Spectral Studies ◽  
Metal Alkoxides ◽  
Nmr Studies ◽  
Mass Spectral ◽  
Elemental Analyses ◽  
Derivatives Of ◽  
Spectroscopic Characterisation

Reaction of VO(OPri)3 with two equivalents of N-phenyldiethanolamine (PhDEAH2) yields a homometallic complex [VO(PhDEA)(PhDEAH)] 1, which reacts with a number of metal alkoxides to afford heterobimetallic oxovanadium(V) complexes of the types [VO(PhDEA)2{M(OR)n-1}] [where PhDEA = C6H5N(CH2CH2O–)2], [M =: Al (n = 3, R = Pri) 2; Al (n = 3, R = But) 3; Ti (n = 4, R = Pri) 4; Zr (n = 4, R = Pri) 5; Nb (n = 5, R = Pri) 6; Ta (n = 5, R = Pri) 7. The derivative [VO(PhDEA)(OSiPh3)] 8 has been prepared by the equimolar interaction of [VO(PhDEA)(OPri)] with Ph3SiOH. All of these complexes have been characterised by spectroscopic (IR; 1H, 13C, 27Al and 51V NMR) studies, elemental analyses, and molecular weight measurements. The derivative 2 has also been characterised by FAB mass spectral studies, which supports for its monomeric nature.

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