0000000000309325
AUTHOR
Yolanda Molina
showing 5 related works from this author
ChemInform Abstract: Preparation of N,O-Aminals as Synthetic Equivalents of H2C=NAr and (H2C=NHAr)+ Ions: Neutral- and Acid-Promoted Transformations.
1988
A general method for the synthesis of N,O-aminals derived from primary aromatic amines is described. The reactivity of these compounds under neutral and acidic conditions has been studied and the title compounds can be envisaged as general purpose H2CNAr or (H2CNHAr)+ equivalents. N,O-Aminals have been converted into perhydrotriazines by moderate heating and into bis(4-aminoaryl)methane derivatives or N-benzylarylamines, respectively when heated in acidic media with pH control. Reduction of N,O-acetals with sodium cyanoborohydride has revealed that the C–O bond is broken exclusively in acidic media.
Preparation of N,O-Aminals as Synthetic Equivalents of H2C=NAr and (H2C=NHAr)+ Ions: Neutral and Acid-promoted Transformations
1988
A general method for the synthesis of N,O-aminals derived from primary aromatic amines is described. The reactivity of these compounds under neutral and acidic conditions has been studied and the title compounds can be envisaged as general purpose H2C=NAr or (H2C=NHAr)+ equivalents. N,O-Aminals have been converted into perhydrotriazines by moderate heating and into bis(4-aminoaryl) methane derivatives or N-benzylarylamines, respectively when heated in acidic media with pH control. Reduction of N, O-acetals with sodium cyanoborohydride has revealed that the C-O bond is broken exclusively in acidic media.
A simple and general synthesis of symmetrical and unsymmetrical bis(arylamino)methanes. Reactions of N,O‐acetals with nitrogen bases
1988
Bis(arylamino)methanes 4 free of amine contamination have been efficiently synthesized from N,O-acetals 1 following three different methodologies. The first two are useful for symmetrical aminals and involve the decomposition of an N,O-acetal by a base (phenyllithium or a lithium arylamide) and trapping of the resulting methyleneamine 2 by the equimolar amount of the corresponding arylamine. The third method allows the preparation of either symmetrical or unsymmetrical aminals and consists of decomposing the starting N,O-acetal 1 by heating in vacuo in the presence of the desired arylamine. Ein einfacher und allgemeiner Zugang zu symmetrischen und unsymmetrischen Bis(arylamino)methanen. Rea…
ChemInform Abstract: A Simple and General Synthesis of Symmetrical and Unsymmetrical Bis(arylamino)methanes. Reactions of N,O-Acetals with Nitrogen B…
1988
Bis(arylamino)methanes 4 free of amine contamination have been efficiently synthesized from N,O-acetals 1 following three different methodologies. The first two are useful for symmetrical aminals and involve the decomposition of an N,O-acetal by a base (phenyllithium or a lithium arylamide) and trapping of the resulting methyleneamine 2 by the equimolar amount of the corresponding arylamine. The third method allows the preparation of either symmetrical or unsymmetrical aminals and consists of decomposing the starting N,O-acetal 1 by heating in vacuo in the presence of the desired arylamine. Ein einfacher und allgemeiner Zugang zu symmetrischen und unsymmetrischen Bis(arylamino)methanen. Rea…
Biomonitoring of mercury in hair of children living in the Valencian Region (Spain). Exposure and risk assessment.
2018
Abstract In this study, we assessed total mercury levels in hair specimens of 661 children, aged 6 to 11, participating in the BIOVAL programme, a human biomonitoring study carried out by the Health Department of the Regional Government of Valencia (Spain). The reference value (95th percentile) determined for this population, within this programme, was 3.25 μg g−1. Hg concentrations ranged between 0.03 μg g−1 and 8.71 μg g−1, with a geometric mean of 0.79 (CI 95%: 0.73–0.85) μg g−1. This mean value was five times higher than the average levels found in children of 17 other European countries (0.145 μg g−1). About 13% of children had hair mercury levels above the FAO/WHO JECFA guideline of 2…