The intermediate 2 was characterized by FT-IR (cm-1) 3244 (1AdegNH str.), 3115 (2AdegNH str.) and 1698 (C=O amide).Finally, the synthesis of titled compounds, (3a-3f) was afforded by reacting compound 2 with different aromatic and heteroaryl aldehydes in presence of acidic condition via nucleophilic addition reaction
It can generate pentabasic 1,3-oxazole which is an important compound in both synthetic chemistry  and biochemistry [6-9] through [3 + 2] ring addition reaction
We have recently proposed an efficient synthetic process for dehydrative glycosylation that consists of two elemental reactions, intramolecular dehydration and the subsequent addition reaction
Elastosil LR 3020/60 is a two-component liquid silicone rubber compound which is optimized for injection molding and vulcanizes rapidly via a platinum-catalyzed addition reaction
. A special feature is said to be its high steam resistance once the silicone is cured.
PDMS with either vinyl or hexenyl groups is crosslinked with hydride-functional PDMS chains via a hydrosilylation or addition reaction
. Curing is very rapid, and, in fact, inhibitors, such as acetylenic alcohols and maleates, are often added to the coating formulation to prevent unwanted cure at room temperature and to maximize working bath life.
In general, a combination of an epoxy resin and a primary amine leads to two principal reactions of (a) the addition reaction
of a primary amine hydrogen to an epoxy group to form a secondary amine and (b) the addition reaction
of an amine hydrogen in the secondary amine to another epoxy group to create a tertiary amine [21, 22],
In the field of advanced organic synthesis, Michael addition reaction
is one of the most powerful tools for carbon-carbon bond construction reactions [1-6].
After the complete addition reaction
mixture was allowed at room temperature and refluxed for 2 to 3h in water bath, the reaction mixture was allowed to cool at room temperature and the precipitate obtained was filtered, dried, and recrystallized from ethanol to give a pure 4,5,6,7-tetrahydro-2H-indazole-3-carbohydrazide 3 as a white crystal in 85% yield, Mp--128-130[degrees]C.
The principle of the method is based on the discoloration of yellowish color of a [beta]-carotene solution due to the breaking of [beta]-conjugation by addition reaction
of lipid or lipid peroxyl radical ([L.sup.*] or LO[O.sup.*]) to a C=C-double bond of [beta]-carotene.
The CASSCF calculations present that the evolution path from FC to CI is barrierless for asynchronous mode while it has to overcome 0.8 eV barrier in synchronous addition reaction
. It suggests asynchronous pathway is a favored predominant pathway for [2 + 2] photocycloaddition reaction between benzene and ethylene, in accord with simulation results.