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The reaction of phosphorus pentachloride (PCl 5) with phosphorus pentoxide (P 4 O 10). 6 PCl 5 + P 4 O 10 → 10 POCl 3. The reaction can be simplified by chlorinating a mixture of PCl 3 and P 4 O 10, generating the PCl 5 in situ. The reaction of phosphorus pentachloride with boric acid or oxalic acid: [12] 3 PCl 5 + 2 B(OH) 3 → 3 POCl 3 + B ...
The reaction of pyridine with bromomethyl ketones gives the related pyridinium salt, wherein the methylene group is highly acidic. This species undergoes a Michael-like addition to α,β-unsaturated carbonyls in the presence of ammonium acetate to undergo ring closure and formation of the targeted substituted pyridine as well as pyridinium bromide.
The reaction of a substituted amide with phosphorus oxychloride gives a substituted chloroiminium ion (2), also called the Vilsmeier reagent. The initial product is an iminium ion (4b), which is hydrolyzed to the corresponding ketone or aldehyde during workup. [7] The Vilsmeier–Haack reaction
This reaction is used to produce around 10,000 tonnes of PCl 5 per year (as of 2000). [6] PCl 3 + Cl 2 ⇌ PCl 5 (ΔH = −124 kJ/mol) PCl 5 exists in equilibrium with PCl 3 and chlorine, and at 180 °C the degree of dissociation is about 40%. [6] Because of this equilibrium, samples of PCl 5 often contain chlorine, which imparts a greenish ...
One classic reaction is the Chichibabin reaction (Aleksei Chichibabin, 1914) in which pyridine is reacted with an alkali-metal amide such as sodium amide to form 2-aminopyridine. [6] In the compound methyl 3-nitropyridine-4-carboxylate, the meta nitro group is actually displaced by fluorine with cesium fluoride in DMSO at 120 °C. [7]
It contains a molybdenum(VI) center with multiple oxygen ligands, coordinated with pyridine and HMPA ligands, although the HMPA can be replaced by DMPU. [2] It is an electrophilic source of oxygen that reacts with enolates and related structures, and thus can be used for alpha- hydroxylation of carbonyl -containing compounds. [ 3 ]
Compared to benzene, the rate of electrophilic substitution on pyridine is much slower, due to the higher electronegativity of the nitrogen atom. Additionally, the nitrogen in pyridine easily gets a positive charge either by protonation (from nitration or sulfonation) or Lewis acids (such as AlCl 3) used to catalyze the reaction. This makes the ...
The Sarett oxidation is an organic reaction that oxidizes primary and secondary alcohols to aldehydes and ketones, respectively, using chromium trioxide and pyridine.Unlike the similar Jones oxidation, the Sarett oxidation will not further oxidize primary alcohols to their carboxylic acid form, neither will it affect carbon-carbon double bonds. [1]