Mónica E. Hedrera

A Convenient Synthesis of Unsymmetrical N,N′-Disubstitutedα,ω-Diaminoalkanes

Abstract A general procedure is described for regiospecific construction of unsymmetrical N-alkyl (or aralkyl)-N′-aryl-α,ω-diaminoalkanes 3 (n=2,3,4) by reduction of N-(ω -arylaminoalkyl)amides 2 with borane. Compounds 2 are readily obtained by condensation of N-(ω-haloalkyl)amides 1 with aromatic amines.

Mass Spectra of Cyclic Amidines and their Salts. Part I: 1,2-diaryl-lH-4,5-Dihydro- Imidazoles and their Corresponding Methiodides.

Abstract Mass spectra under electron impact of certain l,2-diaryl-lH-4,5-dihidroimidazoles (1) and their corresponding l,2-diaryl-3-methyl-lH-4,5-dihydroimidazolium iodides (2) were measured and their patterns analyzed. A fragmentation model is proposed for both series of compounds.

HPTLC monitoring of the biocatalytic synthesis of quinoxalinone derivatives in a one-pot reaction

High-performance thin-layer chromatography has been used to follow the synthesis of some quinoxalinone derivatives by biocatalysis in a one-pot reaction, as an alternative route to the poor Hinsberg reaction. The progress of the one-pot reactions can be followed by HPTLC without previous isolation of the different intermediates arising from them. Biocatalytic synthesis of quinoxalinone derivatives leads to an irreversible reaction which gives a single product of high purity and yields in excess of 90–95%.

A NEW SYNTHETIC APPROACH TO N,N′-DISUBSTITUTED 1,n-ALKANEDIAMINES

A general procedure is described for the synthesis of unsymmetrically substituted N-aryl-N′-alky1 (or aryl) 1,n-alkanediamines 1 (n = 2−5) by reduction of ω-alkyl (or aryl) aminoalkanamides 2 with borane. Compounds 2 are easily obtained by aminolysis of the corresponding ω-haloalkanamides 3.

Mass Spectra of Cyclic Amidines and Their Salts. Part II. 2-Aryl and L, 2-Diaryl-l, 4, 5, 6-Tetrahydropyrimidines and Their Corresponding Methiodides

Abstract Mass spectra of a series of 2-mono- and 1, 2-disubstituted- 1, 4, 5, 6-tetra hydropyrimidines 1 and their methiodides 2 under electron impact (EI) are analyzed. A typical fragmentation pattern was found for each series of compounds. One of the fragmentation routes proposed for compounds 1 was confirmed by high resolution techniques. A fast atom bombardment (FAB+) technique was employed in order to detect methiodides 2 molecular ion. The chemical ionization (CI) spectrum of compound 2d is also analyzed.

Conformational Analysis of Seven Membered Nitrogen Heterocycles Employing Molecular Modeling. Part II: 1-(ONitrophenyl)-2-Phenyl-1h-4,5,6,7-Tetrahydro-1,3-Diazepine

Geometry optimization of 1-(o-nitrophenyl)-2-phenyl-1H-4,5,6,7-tetrahydro-1,3-diazepine is performed by means of molecular modeling. Results are correlated with theoretical and experimental UV spectra.