It is obtained by the oxidation of xanthene (methylene diphenylene oxide) with chromic acid; by the action of phosphorus oxychloride on disodium salicylate; by heating 2 2'-dioxybenzophenone with concentrated sulphuric acid; by distilling fluoran with lime; by the oxidation of xanthydrol (R.
This tetrahedral configuration is based on the existence of only one methylene dichloride, two being necessary if the carbon valencies were directed from the centre of a plane square to its corners, and on the existence of two optical isomers of the formula C. A.
(methylene) groups and the molecule consists of a single chain; such hydrocarbons are referred to as being normal; (2) has a branch and contains the group; CH (methine) in which the free valencies are attached to carbon atoms; such hydrocarbons are termed secondary or iso-; (3) is characterized by a carbon atom linked directly to four other carbon atoms; such hydrocarbons are known as tertiary.
A larger and more important series of condensations may be grouped together as resulting from the elimination of the elements of water between carbonyl (CO) and methylene (CH 2) groups.
Methylene oxide if we assign to it the formula H 2 C O CH 2, but if the formula H 2 C O CH 2 (which assumes the presence of two free valencies) be accepted, the calculated and observed heats of formation are in agreement.
Pyrrol is readily converted into pyridine derivatives by acting with bromoform, chloroform, or methylene iodide on its potassium salt, t3-brom-and O-chlorpyridine being obtained with the first two compounds, and pyridine itself with the last.
Conversely, by heating protocatechuic acid with potash and methylene iodide, piperonylic acid was regained.
These results show that piperonylic acid is the methylene ether of protocatechuic acid.
Methylene iodide, CH 2 I 2, has a density of 3.33, and may be diluted with benzene.
In the "diffusion column" method, a liquid column uniformly varying in density from about 3.3 to I is prepared by pouring a little methylene iodide into a long test tube and adding five times as much benzene.
There are polymers which have hardly any inter-relations other than identity in composition; on the other hand, there are others which are related by the possibility of mutual transformation; examples of this kind are cyanic acid (Cnoh) and cyanuric acid (Cnoh) 3, the latter being a solid which readily transforms into the former on heating as an easily condensable vapour; the reverse transformation may also be realized; and the polymers methylene oxide (CH 2 O) and trioxymethylene (CH20)3.
A little hydrochloric acid, methylene diresorcin [(HO) 2 C 6 H 3] 2 CH 2, whilst with chloral hydrate, in the presence of potassium bisulphate, it yields the lactone of tetra-oxydiphenyl methane carboxylic acid (J.
Ramsay, Ber., 1877, 10, p. 736); by heating pyrrol with sodium methylate and methylene iodide to 200° C. (M.
POLYMETHYLENES, in chemistry, cyclic compounds, the simplest members of which are saturated hydrocarbons of general formula C 7, H 2nj where n may be r to 9, and known as tri-, tetra-, penta-, hexa-, and hepta-methylene, &c., or cyclo- propane, -butane, -pentane, -hexane, -heptane, &c.: - CH 21 CH 2 CH 2 CH2.CH2 CH2 CH2 CH2?C1H,, I I H ?
C 6 H 7 0, is obtained by condensing sodium aceto-acetate with methylene iodide, the ester so formed being then hydrolysed.
3dicarboxylic acids) are obtained by the action of methylene iodide on disodio-pentane tetracarboxylic ester (W.