Mass spectrometry of 5-alkoxyisoxazoles and isoxazol-5-ones

Nishiwaki, Tarozaemon

doi:10.1016/0040-4020(69)85007-6

Cited by 26 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…EI mass spectrum was in accordance with a published one. 16 The fragmentation pattern of the 3-methyl-2-isoxazolin-5-one may be deduced from the MS/MS results and it confirms that if loss of N-0-CO is well displayed by isoxazolin-5-ones the mechanism occurs in two steps (Scheme 14).16…”

Section: Scheme 13supporting

confidence: 53%

Study of reactions induced by hydroxylamine treatment of esters of organic acids and of 3-ketoacids: Application to the study of urines from patients under valproate therapy

Libert

Draye

Hoof

et al. 1991

Biol. Mass Spectrom.

View full text Add to dashboard Cite

Hydroxylamine used at alkaline pH as oximating agent in the search for organic aciduria by gas chromatography/mass spectrometry (GC/MS) induces other chemical reactions. Esters are partially transformed in their corresponding hydroxamic acids. GC/MS characteristics of the trimethylsilylated derivatives of the hydroxamic acids arising from alpha-unsaturated esters are here reported. Their mass spectral fragmentation helps in the recognition of peaks arising from the glucuronides of 2-ene- and probably 2,3'-diene-valproic acid. By heating in the injection port of the gas chromatograph, part of some trimethylsilylated hydroxamic acids are transformed to the corresponding isocyanates by a Lossen-like rearrangement. In addition to the corresponding hydroxamic acids, hydroxylamine treatment of alpha-unsaturated esters forms 2-isoxazolidin-3-ones by intramolecular Michael addition. GC/MS characteristics of the trimethylsilylated derivatives of these compounds are reported. Submitted to hydroxylamine, 3-ketoacids forms 2-isoxazolin-5-ones by cyclization of the oximes after acidification. This explains the existence of two GC peaks observed from urine extracts of patients under valproate therapy, which correspond to two tautomers of 2-isoxazolin-5-one originating from the oximes of the 3-keto-valproic acid.

show abstract

Section: Scheme 13supporting

confidence: 53%

Study of reactions induced by hydroxylamine treatment of esters of organic acids and of 3-ketoacids: Application to the study of urines from patients under valproate therapy

Libert

Draye

Hoof

et al. 1991

Biol. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…The 3-(4-methylsulfonylphenyl)-5-alkylthioisoxazole showed characteristic peaks due to loss of -SR and -COSR fragment (M-47 and M-75 in the case of 5-methylthio isomer) suggesting that the alkylthio group is adjacent to the ring O-atom [15,16].…”

mentioning

confidence: 97%

“…In vivo pharmacological evaluation of compounds 12-14, 16 and 17 was carried out to assess their potential anti-inflammatory activity. Qualitative structure-activity relationship data, acquired using the anti-inflammatory rat paw edema assay [22], showed this group of C-5 alkylthio substituted 3,4-diarylisoxazoles exhibits anti-inflammatory activity with excellent activity range.…”

mentioning

confidence: 99%

A convenient synthesis of 5‐alkylthio‐3,4‐diarylisoxazoles by palladium‐catalyzed coupling reactions

Eskandari

Navidpour

Amini

et al. 2007

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

show abstract

“…A clear distinction of regioselectivity of above reaction could be made by means of mass spectral fragmentation. The 3-(4-methylsulfonylphenyl)-5-alkylthioisoxazole showed characteristic peaks due to loss of -SR and -COSR fragment (M-47 and M-75 in the case of 5-methylthio isomer) suggesting that the alkylthio group is adjacent to the ring O-atom [15,16].…”

mentioning

confidence: 99%

mentioning

confidence: 99%

A Convenient Synthesis of 5‐Alkylthio‐3,4‐diarylisoxazoles by Palladium‐Catalyzed Coupling Reactions.

et al. 2007

View full text Add to dashboard Cite

A Convenient Synthesis of 5-Alkylthio-3,4-diarylisoxazoles by Palladium-Catalyzed Coupling Reactions. -The title compounds (VIII) are tested for their anti-inflammatory activity. Derivative (VIIIa) reduces inflammation by 85% at 3 h post drug administration. -(ESKANDARI, R.; NAVIDPOUR, L.; AMINI, M.; SHAFAROODI, H.; SHAFIEE*, A.; J. Heterocycl. Chem. 44 (2007) 2, 449-453; Dep. Chem., Fac. Pharm., Med. Sci. Univ. Tehran, Tehran, Iran; Eng.) -H. Haber 32-130

show abstract

Mass spectrometry of 5-alkoxyisoxazoles and isoxazol-5-ones

Cited by 26 publications

References 18 publications

Study of reactions induced by hydroxylamine treatment of esters of organic acids and of 3-ketoacids: Application to the study of urines from patients under valproate therapy

Study of reactions induced by hydroxylamine treatment of esters of organic acids and of 3-ketoacids: Application to the study of urines from patients under valproate therapy

A convenient synthesis of 5‐alkylthio‐3,4‐diarylisoxazoles by palladium‐catalyzed coupling reactions

A Convenient Synthesis of 5‐Alkylthio‐3,4‐diarylisoxazoles by Palladium‐Catalyzed Coupling Reactions.

Contact Info

Product

Resources

About