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Pyridinium perbromide (also called pyridinium bromide perbromide, pyridine hydrobromide perbromide, or pyridinium tribromide) is an organic chemical composed of a pyridinium cation and a tribromide anion. It can also be considered as a complex containing pyridinium bromide—the salt of pyridine and hydrogen bromide—with an added bromine (Br ...
Pyridinium refers to the cation [C 5 H 5 NH] +. It is the conjugate acid of pyridine . Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines.
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 ...
4-Methylpyridine is the organic compound with the formula CH 3 C 5 H 4 N. It is one of the three isomers of methylpyridine.This pungent liquid is a building block for the synthesis of other heterocyclic compounds.
Methylpyridinium is prepared by treating pyridine with dimethylsulfate: [2]. C 5 H 5 N + (CH 3 O) 2 SO 2 → [C 5 H 5 NCH 3] + CH 3 OSO − 3. It is found in some coffee products. [3] It is not present in unroasted coffee beans, but is formed during roasting from its precursor chemical, trigonelline. [3]
2-Bromopyridine reacts with butyllithium to give 2-lithiopyridine, [2] which is a versatile reagent. [3] Pyrithione can be prepared in a two-step synthesis from 2-bromopyridine by oxidation to the N-oxide with a suitable peracid followed by substitution using either sodium dithionite or sodium sulfide with sodium hydroxide to introduce the thiol functional group.
Molar mass: 157.998 g·mol −1 Appearance colorless liquid Density: 1.640 g/cm 3: Melting point: −27 Boiling point: 173 °C (343 °F; 446 K) Hazards GHS labelling:
The main use for phosphorus tribromide is for conversion of primary or secondary alcohols to alkyl bromides, [9] as described above.PBr 3 usually gives higher yields than hydrobromic acid, and it avoids problems of carbocation rearrangement- for example even neopentyl bromide can be made from the alcohol in 60% yield.