Cesium hydroxide synthesis

Yield:-

Reaction Conditions:

with hydrogenchloride;caesium carbonate in 5,5-dimethyl-1,3-cyclohexadiene;[⁽²⁾H₆]acetone;water;dimethyl sulfoxide

Steps:

A.2 Concentration of Caesium Hydroxide of 0.3 Equivalent
Example A.2
Concentration of Caesium Hydroxide of 0.3 Equivalent
A suspension of 50.6 g of p-(benzyloxy)phenol (0.254 mol), 20 g (0.667 mol) of paraformaldehyde (melting point: 135° C.) in 700 ml of xylene is placed under argon in a 2-litre three-necked flask equipped with a mechanical stirrer and a "Dean-Stark" type water trap.
The suspension is heated with stirring.
When the temperature reaches 90° C., 14.8 ml (0.085 mol) of a solution of CsOH at 50% (by weight) in water is added rapidly using a syringe (and under flushing with argon).
The suspension is left under reflux for 5 h 30.
Then a perfectly clear bright orange solution is obtained.
100 ml of a solution of 37% HCl in water is then added, and the formation of a precipitate is observed.
The suspension is left under vigorous stirring for two days, then evaporated to dryness in a rotavapor.
After washing with 500 ml of water (removal of the salts and excess HCl), the solid is dissolved hot (130° C.) in 200 ml of DMSO. Then a clear solution black is obtained, to which 2 l of acetone is added hot.
After returning to ambient temperature, this clear solution is left for a week, during which a crystalline precipitate of p-(benzyloxy)calix[6]arene (18 g) is deposited on the walls of flask.
The filtrate is evaporated in a rotary evaporator, then with a heat gun until a black solid is obtained.
This solid is washed with acetone, which leads to the recovery of a second batch of p-(benzyloxy)calix[6]arene (10 g). Total: 28 g, yield 51%.

References:

UNIVERSITE PARIS-SUD XI;Huc, Vincent Germain;Martini, Cyril US2015/232603, 2015, A1

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