Features of 3-amino-5-methylisoxazole in heterocyclizations involving pyruvic acids

Crystal structure of 1H-imidazole-1-methanol

The crystal structure of methanol imidazole featuring a tri-mol­ecule hydrogen-bonded macrocycle is described.

The synthesis and the crystal structure of 1H-imidazole-1-methanol, C₄H₆N₂O, are described. This compound comprises an imidazole ring with a methanol group attached at the 1-position affording an imine nitro­gen atom able to receive a hydrogen bond and an alcohol group able to donate to a hydrogen bond. This imidazole methanol crystallizes with monoclinic (P2₁/n) symmetry with three symmetry-unique mol­ecules. These three mol­ecules are connected via O—H⋯N hydrogen bonding in a head-to-tail configuration to form independent three-membered macrocycles.

Stereoselective, Multicomponent Approach to Quaternary Substituted Hydroindole Scaffolds

The Amaryllidaceae alkaloids have been a target of synthesis for decades due to their complex architectures and biological activity. A central feature of these natural product cores is a quaternary substituted hydroindole heterocycle. Building off the foundation of our previous multicomponent approach to highly functionalized pyrrolidinones, herein we report a highly convergent, diastereoselective, multicomponent approach to access the hydroindole cores present within crinine, haemanthamine, pretazettine, and various other bioactive alkaloids. These scaffolds are additionally useful as building blocks for druglike molecules and natural product like library generation.

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

Four-component reactions of 3-amino-1,2,4-triazole or 5-amino-1H-pyrazole-4-carbonitrile with aromatic aldehydes and pyruvic acid or its esters under ultrasonication were studied. Unusual for such a reaction type, a cascade of elementary stages led to the formation of 7-azolylaminotetrahydroazolo[1,5-a]pyrimidines.