Ethers are quite stable compounds. These are not easily attacked by alkalies, dilute mineral acids, active metals, reducing agents or oxidising agents under ordinary conditions.
(i) Reaction with acids : Being Lewis bases, ethers form complexes with Lewis acids such as BF3, AlCl3, FeCl3, etc. These complexes are called etherates.
Similarly, diethyl ether reacts with Grignard reagent forming Grignard reagent etherate.
Due to the formation of the etherate, Grignard reagents dissolve in ether. That is why Grignard reagents are usually prepared in ethers. However, they cannot be prepared in benzene, because benzene has no lone pair of electrons and therefore, cannot form complexes with them.
(ii) Action of hydroiodic acid
(a) With cold HI
(b) With hot HI
R – O – R' + 2HI ——————→ RI + R'I + H2O
(iii) Zeisel method : RI + AgNO3 (alc.) → AgI ↓ + RNO3
•The silver iodide thus form can be detected and estimated. This is the basis of Zeisel method for the detection and estimation of alkoxy group in a compound.
(iv) Action of PCl5
R – O – R + PCl5 ————→ 2RCl + POCl3. There is no reaction in cold.
(v) Reaction with acetyl chloride
(vi) Reaction with acid anhydride
CH3CO . O . OCCH3 + C2H5 . O . C2H5 —————→ 2CH3COOC2H5
Acetylchloride Diethyl ether heat Ethyl acetate
(viii) Reaction with carbon mono oxide
(ix) Action of bases