求有关乙酰氯的英文文献,1000词左右,只要内容相关.
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求有关乙酰氯的英文文献,1000词左右,只要内容相关.
求有关乙酰氯的英文文献,1000词左右,只要内容相关.
求有关乙酰氯的英文文献,1000词左右,只要内容相关.
In organic chemistry, an acyl chloride (or acid chloride) is an organic compound which is a reactive derivative of a carboxylic acid. As part of its molecular structure, an acyl chloride has the reactive functional group -CO-Cl and has the general formula RCOCl, where R is an organic radical group.
Acyl chlorides are a subset of acyl halides and undergo many of the same chemical reactions. A specific example of an acyl chloride is acetyl chloride, CH3COCl.
Acyl chlorides are generally prepared in the same manner as alkyl chlorides: by replacing the corresponding hydroxy substituents with chlorides. Acyl chlorides are often prepared by reacting a carboxylic acid with thionyl chloride (SOCl2), phosphorus trichloride (PCl3), or phosphorus pentachloride (PCl5):[1]
R-COOH + SOCl2 → R-COCl + SO2 + HCl
3 R-COOH + PCl3 → 3 R-COCl + H3PO3
R-COOH + PCl5 → R-COCl + POCl3 + HCl
The reaction with thionyl chloride may be catalyzed by dimethylformamide.[2] In this reaction, the sulfur dioxide (SO2) and hydrogen chloride (HCl) generated are both gases which can leave the reaction vessel, driving the reaction forward. Excess thionyl chloride (b.p. 79 °C) is easily evaporated as well.[1] The reaction mechanism involving thionyl chloride and phosphorus pentachloride are similar; the mechanism with thionyl chloride is illustrative:
Acyl chlorides tend to be liquids, which may react with atmospheric moisture to give fumes in air. Lacking the ability to form hydrogen bonds, they have lower boiling points than similar carboxylic acids (e.g. acetic acid, b.p. 118 °C; acetyl chloride, b.p. 51 °C). Like all carbonyl compounds, infrared spectroscopy reveals a band near 1800 cm−1.
Another method involves the use of oxalyl chloride:
R-COOH + ClCOCOCl → R-COCl + CO + CO2 + HCl
The reaction is catalysed by dimethylformamide; DMF reacts with oxalyl chloride in the first step to give the iminium intermediate.