Novel Procedure for Selective C-Nitrosation of Aminopyrimidine Derivatives Under Neutral Conditions. Scope and Synthetic Applications
作者:Antonio Marchal、Manuel Melguizo、Manuel Nogueras、Adolfo Sánchez、John N. Low
DOI:10.1055/s-2002-19760
日期:——
A novel simple method, based on treatment with isoamyl nitrite (IAN) in DMSO without any added acid, to produce selective C(5)-nitrosation of aminopyrimidine derivatives is described. It proved to be suitable for a multigram scale and applicable to a larger range of pyrimidine derivatives, including amino-dialkoxypyrimidines, than the procedures previously known. Its scope is analyzed and some example on the usefulness of the newly prepared substances as intermediates in the synthesis of fused heterobicyclic derivatives of potential biological interest is presented.
Amino-substituted O<sup>6</sup>-benzyl-5-nitrosopyrimidines: interplay of molecular, molecular-electronic and supramolecular structures
作者:Antonio Quesada、Antonio Marchal、Manuel Melguizo、Manuel Nogueras、Adolfo Sánchez、John N. Low、Debbie Cannon、Dorcas M. M. Farrell、Christopher Glidewell
DOI:10.1107/s0108768101021607
日期:2002.4.1
containing the N-alkyl substituents -NHCH(2)COOEt, -NHCH(2)CH(2)COOEt and -NHCH(CH(2)Ph)COOEt, derived from amino acid esters, exhibit a rich variety of conformational behaviour, and in all of the nitroso compounds the bond lengths provide strong evidence for a highly polarized electronic structure. Associated with this polarization is extensive charge-assisted hydrogen bonding between the molecules, leading
2-Amino-4,6-bis(benzyloxy)-5-nitrosopyrimidine: chains built from three-centre N—H...(N,O) and N—H...π(arene) hydrogen bonds
作者:Antonio Quesada、John N. Low、Manuel Melguizo、Manuel Nogueras、Christopher Glidewell
DOI:10.1107/s0108270102008181
日期:2002.6.15
The molecules of the title compound, C(18)H(16)N(4)O(3), exhibit a very polarized molecular-electronic structure. The molecules are linked into chains by a combination of an asymmetric three-centre N[bond]H...(N,O) hydrogen bond [H...N 2.19, H...O 2.54, N...N 3.041 (4) and N...O 2.977 (4) A, and N[bond]H...N 168, N[bond]H...O 112 and N...H...O 67 degrees ] and an N[bond]H...pi(arene) interaction [H...Cg 2.67 A, N...Cg 3.496 (4) A and N[bond]H...Cg 163 degrees; Cg is a benzyl ring centroid].
Alkoxy-5-nitrosopyrimidines: Useful Building Block for the Generation of Biologically Active Compounds
作者:Antonio Marchal、Manuel Nogueras、Adolfo Sánchez、John N. Low、Lieve Naesens、Erik De Clercq、Manuel Melguizo
DOI:10.1002/ejoc.201000195
日期:——
Several alkoxy-5-nitrosopyrimidines were synthesised and high regioselective and sequential nucleophilic aromatic substitution of methoxy groups in 2-amino-4,6-dimethoxy-5-nitrosopyrimidine was observed. The approach was applied to the synthesis of valuable polyfunctionalised aminopyrimidines capable of mimicking fused heterobicyclic derivatives of biological interest. In addition, new compounds were