Organic Syntheses, CV 4, 178
Submitted by Norman G. Gaylord and P. M. Kamath
1.
Checked by R. T. Arnold and J. John Brezinski.
1. Procedure
To a mixture of
138.1 g. (1 mole) of salicyclic acid and
128.6 g. (1 mole) of p-chlorophenol in a
2-l. round-bottomed flask fitted with a thermometer reaching to the bottom of the flask and a reflux condenser with a drying tube (Note
1) is added
58.3 g. (0.38 mole) of phosphorus oxychloride. The mixture is heated with occasional swirling, and the temperature is maintained at 75–80°. At the end of 4 hours the reactants have been reduced to a molten mass, and this is poured slowly, with vigorous stirring, into a solution of
120 g. of sodium carbonate in 800 ml. of water. The precipitated ester is collected on a filter and washed with four 200-ml. portions of water. The yield of crude, air-dried,
p-chlorophenyl salicylate is
174–189 g. (
70–76%); m.p.
65–66°. Recrystallization from
absolute ethanol yields
136–154 g. (
55–62%) of pure product; m.p.
69.5–70.5°. A second crop may be obtained by concentration of the filtrate from the first crop or by the addition of water (Note
2).
2. Notes
1. It is advisable to attach the drying tube to a
water trap2 in order to prevent the escape of
hydrogen chloride into the atmosphere.
2. The above method has been used in the preparation of other substituted phenyl salicylates to give the following yields of recrystallized products with the indicated melting points.
These esters, with the exception of the
p-nitrophenyl derivative, can be recrystallized from absolute
ethanol. The nitro compound is recrystallized from
dioxane.
3. Discussion
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