In later processes, carnallite (a natural double chloride of magnesium and potassium) has commonly, after careful dehydration, been substituted for the single chloride.
It probably represents the partial dehydration of limonite, and by further loss of water may pass into haematite or red iron ore.
The carbonate, being insoluble in strong alcohol (and many other liquid organic compounds), is much used for dehydration of the corresponding aqueous preparations.
-> CH3C6H5CONHC6H51 N OH Syn-phenyltolylketoxime CH3 C6H4 C C6H5 CH3C6H4NH000,H5 HO N A nti-tolylphenylketoxime In the case of the aldoximes, that one which most readily loses the elements of water on dehydration is assumed to contain its hydroxyl radical adjacent to the movable hydrogen atom and is designated the syn-compound.
Acetonyl-acetophenone, C6H5.CO.CH2.CH2.CO.CH3, is produced by condensing phenacyl bromide with sodium acetoacetate with subsequent elimination of carbon dioxide, and on dehydration gives aa-phenyl-methyl-furfurane.