1,3-Dimethyl-1H-indazol-6-amine.
Summary
The molecular structure of C(9)H(11)N(3) is nearly planar. Hydrogen bonds in the crystal structure arrange the molecules into a specific packing formation.
Area of Science:
- Crystallography
- Molecular Chemistry
Background:
- Understanding the three-dimensional arrangement of atoms in molecules is crucial for predicting their properties and interactions.
- Crystal packing influences macroscopic material characteristics.
Purpose of the Study:
- To determine the precise molecular structure and crystal packing of the compound C(9)H(11)N(3).
- To investigate the role of intermolecular forces, specifically hydrogen bonding, in the observed crystal structure.
Main Methods:
- Single-crystal X-ray diffraction was employed to analyze the crystal structure.
- The molecular geometry and atomic deviations from planarity were quantified.
Main Results:
- The molecular skeleton of C(9)H(11)N(3) was found to be almost planar, with minimal deviation (0.0325(19) Å) at the amino nitrogen atom.
- Intermolecular N-H⋯N hydrogen bonds were identified as the primary force governing the crystal packing.
Conclusions:
- The study elucidates the near-planar molecular conformation of C(9)H(11)N(3).
- Hydrogen bonding plays a significant role in directing the self-assembly and crystal lattice formation of this compound.
Related Concept Videos
Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
Nomenclature of Aryl and Heterocyclic Amines
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.
Nomenclature of Primary Amines
Primary, secondary, and tertiary amines are compounds consisting of one, two, and three alkyl groups connected to the amino group (–NH2), respectively. As depicted in Figure 1, the common name of the primary amines is obtained by adding the suffix -amine to the alkyl substituent attached to the amino group as the corresponding alkylamine.
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.


