Study of the Addition Mechanism of 1 H -Indazole and Its 4-, 5-, 6-, and 7-Nitro Derivatives to Formaldehyde in Aqueous Hydrochloric Acid Solutions

Ibon Alkorta (1) , Rosa Claramunt (2) , José Elguero (1) , Enrique Gutiérrez-Puebla (3) , M. Ángeles Monge (3) , Felipe Reviriego (4) , Christian Roussel (5)

1 CSIC - Instituto de Quimica Médica
2 UNED - Universidad Nacional de Educación a Distancia
3 ICMM - Instituto de Ciencia de Materiales de Madrid
4 CSIC - Consejo Superior de Investigaciones Cientificas [España] = Spanish National Research Council [Spain]
5 ISM2 - Institut des Sciences Moléculaires de Marseille

The reaction of NH-indazoles with formaldehyde in aqueous hydrochloric acid has been experimentally studied by solution and solid-state nuclear magnetic resonance (NMR) and crystallography. The mechanism of the formation of N 1-CH 2 OH derivatives was determined. For the first time, 2-substituted derivatives have been characterized by multinuclear NMR. Theoretically, calculations with gauge-invariant atomic orbitals (GIAOs) at the Becke three-parameter (exchange) Lee−Yang− Parr B3LYP/6-311++G(d,p) level have provided a sound basis for the experimental observations. The first X-ray structures of four (1H-indazol-1-yl)methanol derivatives are reported.

Domaines: Chimie organique; Chimie théorique et/ou physique

Ibon Alkorta, Rosa Claramunt, José Elguero, Enrique Gutiérrez-Puebla, M. Ángeles Monge, et al.. Study of the Addition Mechanism of 1 H -Indazole and Its 4-, 5-, 6-, and 7-Nitro Derivatives to Formaldehyde in Aqueous Hydrochloric Acid Solutions. Journal of Organic Chemistry, 2022, 87 (9), pp.5866-5881. ⟨10.1021/acs.joc.2c00154⟩. ⟨hal-03959333⟩