Hydroquinone hydrogen chloride

CnHiiN 8.67 H2O, Diethylamine hydrate, 32B, 288 CijHiiN 9.75 H2O, t-Butylamine hydrate, 32B, 289 Ci,H2oFNOii, Tetramethylammonium fluoride tetrahydrate, 32B, 291 C4H23NO6, Tetramethylammonium hydroxide pentahydrate, 31B, 282 C6Hg02 0.33 HCl, Hydroquinone hydrogen chloride clathrate, 43B,... 

Dihydroxyacetophenone. Finely powder a mixture of 40 g. of dry hydroquinone diacetate (1) and 87 g. of anhydrous aluminium chloride in a glass mortar and introduce it into a 500 ml. round-bottomed flask, fitted with an air condenser protected by a calcium chloride tube and connected to a gas absorption trap (Fig. II, 8, 1). Immerse the flask in an oil bath and heat slowly so that the temperature reaches 110-120° at the end of about 30 minutes the evolution of hydrogen chloride then hegins. Raise the temperature slowly to 160-165° and maintain this temperature for 3 hours. Remove the flask from the oil bath and allow to cool. Add 280 g. of crushed ice followed by 20 ml. of concentrated hydrochloric acid in order to decompose the excess of aluminium chloride. Filter the resulting solid with suction and wash it with two 80 ml. portions of cold water. Recrystallise the crude product from 200 ml. of 95 per cent, ethanol. The 3 ield of pure 2 5-dihydroxyacetophenone, m.p. 202-203°, is 23 g. 

Hydroquinone monobutyl ether Potassium hydroxide y-Morpholinopropyl chloride Hydrogen chloride... 

Quinone 239 adds hydrogen chloride to give the 6-chloro compound after subsequent oxidation the 7-chloro isomer is obtained as a by-product (870PP249). Reactions with pyridine have been described (58MI3 71JMC1029). With dienes, adducts are formed that can be isomerized with acid into hydroquinones, which can be reoxidized with silver oxide to quinones (67JHC133 73JCS(P 1)2374). 

A mixture of 50 g. (0.257 mole) of dry hydroquinone diacetate (p. 68) and 116 g. (0.87 mole) (Note 1) of anhydrous aluminum chloride is finely powdered in a mortar and introduced into a dry 500-ml. round-bottomed flask fitted with an air condenser protected by a calcium chloride tube and connected to a gas-absorption trap. The flask is placed in an oil bath (Note 2) which is heated slowly from room temperature so that at the end of about hour the temperature of the oil reaches 110-120°, at which point the evolution of hydrogen chloride be ns. The temperature is then raised slowly to 160-165° and maintained at that point for about 3 hours (Note 3) at the end of about 2 hours the evolution of hydrogen chloride becomes very slow and the mass assiunes a green color and becomes pasty in consistency (Note 4). 

Dehydrogenation of pyrocatechol by silver oxide gives 0-benzoquinone.469 For preparation of amino-0-benzoquinones see Homer and Lang.470 Hydro-quinones are also dehydrogenated with success by lead tetraacetate.222 Further, 2,3-dichloro-5,6-dicyano-l,2-benzoquinone is obtained from the hydroquinone in 83% yield when a solution of the latter in 5% ethanolic hydrogen chloride is shaken with a mixture of Pb02 and benzene.471... 

Piozzi et al. (219) have confirmed 317 as the structure of japonine by synthesis (Scheme 27). Application of Darzen s reaction to 2-nitro-5-methoxybenzaldehyde furnished epoxide 314. This was converted with hydrogen chloride and hydroquinone into 315, which was reduced to the 3-hydroxy-4-quinolone 316 methylation then afforded japonine as the major product. 

EXPLOSION and FIRE CONCERNS noncombustible solid, but contact with water may release heat sufficient to ignite combustible materials NFPA rating Health 3, Flammability 0, Reactivity 1 can ignite or react violently with acetic acid, acetaldehyde, acetic anhydride, acrolein, acrylonitrile, allyl chloride, aluminum, chlorine trifluoride, chloroform and methanol, chlorohydrin, chlorosulfonic acid, 1,2-dichloroethylene, glyoxal, hydrogen chloride, hydrogen fluoride, hydroquinone, nitric acid, sulfuric acid, nitroethane, nitropropane, nitromethane, tetra-hydrofuran, water, zinc, and others reacts to form explosive products with ammonia and silver... 

DCE vapors form explosive mixtures with air within the range 7.3-16.0% by volume in air. It polymerizes at elevated temperatures. If polymerization occurs in a closed container, the container may rupture violently. Polymerization is inhibited in the presence of 200 ppm of hydroquinone monomethyl ether (Aldrich 1997). It forms a white deposit of peroxide on long standing which may explode. It decomposes when involved in fire, producing toxic hydrogen chloride. Reactions with concentrated mineral acids are exothermic. 

Matthews and Strange [42] reported a similar reaction of isoprene with sulfur dioxide in the presence of hydrogen chloride. Seyer and King [Id] reported that 1,3-cyclohexadiene reacted with sulfur dioxide to give a white amorphous compound, as earlier reported by Hofmann and Damm [43]. 2-Methyl- and 4-methyl-1,3-pentadiene were reported by Morris and Van Winkle [44] to react with sulfur dioxide to yield a cyclic sulfone and some hydrocarbon polymer. Starkweather [45] in 1945 reported that chloroprene (2-chloro-l,3-butadiene) reacted with sulfur dioxide in an emulsion system to give a copolymer. Poly-sulfone is the major product when radical initiators are used. Cyclic products predominate when radical inhibitors (hydroquinone) or temperatures in excess of the ceiling temperature are used. For example ... 

Boeyens. J.CA. Pretorius, J.A. X-ray and neutron diifrac-tion studies of the hydroquinone clathrate of hydrogen chloride. Acta Crystallogr., Sect. B 1977.33. 2120-2124. 

Low temperature properties of hydroquinone clathrate of small polar molecules are also of interest because of the possibility they offer to the study of low-lying rotational levels of the molecules. In the neat (i.e., non-clathrate) crystal of hydrogen chloride, hydrogen sulphide and other small molecules, strong intermolecular interaction prohibits rotation of the molecules. But a cavity is formed by the rigid host lattice for each of the guest molecules in the clathrate. Therefore, they can rotate rather freely in the approximately spherical potential of the wall. 

Figure 27 Multicomponent crystals designed to stabilize reactive chemical species, (a) Generic chemical structures of each component of benzyl(hexadecyl)dimethylammonium chloride sesquikis(hydroquinone), (b) supramolecular chains comprising hydroquinone and chloride anions, and (c) view of the incorporation of the supramolecular chains shown in (b) within the host assembly comprising the ammonium cations. The 0-H- O and O-H- Cl hydrogen bonds are shown as orange and blue dashed Unes, respectively.

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