Picric acid boiling point

Alkyl chlorides often react more rapidly (50-60 minutes) upon adding 0.5 g of potassium iodide to the original reaction mixture, followed by sufficient water or ethanol to produce a clear solution at the boiling point. After refluxing, 0.5 g of picric acid is added, etc. 

As early as in the first half of the XVIlIth century Glauber obtained picric acid by acting on wool and horn with nitric acid. Soon reactions between nitric acid and a variety of organic substances became one of the alchemical reactions most frequently used. They were usually carried out by heating a substance with nitric acid, often to boiling point. Thus picric acid was obtained from certain organic substances such as indigo, silk, resins, etc... 

Belyaev and Yuzefovich heated nitroglycerin and other explosives in vacuum, and procured the results summarized in the following table. The fact that ignition temperatures are fairly close to probable boiling points indicates that high concentrations of vapor exist at the moment when the substances ignite. The authors point out that TNT, PETN, and picric acid neither... 

PICRIC ACID (88-89-1) CsHjNjO, (dry) (N02)3C6Hj0H (wet, with not <10% water) Flammable solid (flash point 302°F/150°C autoignition temp 572°F/300°C Fire Rating 4). Anhydrous material highly unstable and heat-, friction-, and impact-sensitive explosive (explodes above boiling point, about 572°F/300°C). The presence of trace... 

Preparation of Picrates.—Dissolve 0.1 g. of hydrocarbon (naphthalene, phenanthrenc, or acenaphthene) and 0.2 g. of picric acid in. 5 c c. of boiling 95 per cent alcoliol.. llow the solution to cool gradually. Filter off the yellow crystals, RH CVHiiNOji.OH, and recrystallize from a small amount of alcohol. Dr> on a clay plate and take melting-points. 

Some of the physical constants of pyrrole and of a selection of its derivatives are collected in Table 4,1, The boiling point of pyrrole is higher than might have been expected, and the closer similarity in this property of 1-methylpyrrole to, say, toluene suggests that in pyrrole the imino group is responsible for some sort of association (see below). The characterization of pyrrole and simple alkylpyrroles through the formation of crystalline derivatives is not always easy. Picrates are usually unstable. In cases where picric acid causes dimerization, the dimer picrate is often a satisfactory derivatively, 233 xhe reaction with phenyl isocyanate (p. 66) is useful. 

The ether (5 mmole) is dissolved in 5 ml of boiling chloroform and mixed with 5 mmole of picric acid dissolved in 3 ml of boiling chloroform. On cooling the solution, crystals are formed which are filtered off and dried between two pieces of filter paper. Melting point is determined immediately, because these compounds decompose during recrystallization. 

These alkaloids react readily with picric and aurichloric acids to give nicely crystalline derivatives which, because of the wide spread in their melting points, are the most satisfactory derivatives for the identification of the individual members of this group of alkaloids. There is also a characteristic difference in the aurichloride crystals of atropine and Z-hyoscyamine (20). Atropine aurichloride is a dull lusterless powder which melts in boiling water while Z-hyoscyamine aurichloride crystallizes in glistening golden-yellow leaflets which do not melt in boiling water. 

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