Pyridine picrate

Pyridine Picrate. CsHsN+C6H307N3 golden yel needles mp, 165—66° explds at 432° (Bell 20,208)... 

On the other hand, trinitrocresolates of organic bases are more difficult to dissolve than the corresponding picrates. Solubilities in 100 ml of water of pyridine picrate and pyridine trinitrocresolate are given below for comparison ... 

A mixture of 308 g. (1.0 mole) of dry pyridine picrate, 103 g. (0.67 mole) of phosphorus oxychloride, and 250 ml. of benzene is heated to reflux for 15 minutes. The benzene layer and the precipitated oil are separated and individually given a thorough wash with hot water. Evaporation of the benzene from the solution gives a 73% yield of picryl chloride melting at 79-81°, and from the washed precipitated oil is obtained an additional 25% jrield of product of the same purity. 

It is particularly easy to replace the OH of picric acid by Cl, although this compound reacts with POCl3 only when present as pyridine picrate. 

Picryl chloride 1071 Pyridine (7.9) is added to a hot solution of picric acid (22.9 g) in 95 % alcohol (200 ml) on cooling, pyridine picrate (30.1 g, 98%), m.p. 166°, separates. Dry pyridine picrate (1 mole), POCl3 (0.67 mole), and benzene (250 ml) are boiled under reflux for 15 min the benzene layer and the oil that separates are washed separately with hot water after removal of the benzene, the benzene layer affords 73 % and the oil 25 % of picryl chloride, m.p. 79-81°. 

Vaseline, Castor oil, Olivo oil, Sal volatile, Boracic acid powder, Sodium bicarbonate powder, Chloramiue-T powder. Sulpha-pyridine powder, Butesin picrate ointment. 

Alkylselenazoles are oily alkaline liquids possessing a smell similar to that of the corresponding thiazole or pyridine derivatives. The crystalline picrates or 3-methylselenazolium iodides have been used for the purpose of characterization. Alkyl derivatives are partially soluble in water aryl derivatives are insoluble. 

Specifications, Analysis, and Toxicity. Dicyandiamide is identified quaHtatively by paper chromatography and quantitatively by ultraviolet spectrometry of the chromatogram. More commonly, total nitrogen analysis is used as a purity control or the dicyandiamide is converted by hydrolysis to guanylurea, which is determined gravimetrically as the nickel salt (50). Methods based on the precipitation of silver dicyandiamide picrate are sometimes used (51). Dicyandiamide can also be titrated with tetrabutylammonium hydroxide ia pyridine solution. Table 4 gives a typical analysis of a commercial sample. Dicyandiamide is essentially nontoxic. It may, however, cause dermatitis. 

Chloromethyl)pyridine hydrochloride [1822-51-1] M 164.0, m 170-175°, 172-173°, pK , -5.6. Purified by recrystn from EtOH or EtOH-dry Et20. It melts between 171° and 175° and the clear melt resolidifies on further heating at 190° and turns red to black at 280° but does not melt again. The picrate-hydrochloride (prepared in EtOH) has m 146-147°. The free base is an oil, [Mosher and Tessieri J Am Chem Soc 73 4925 1951.]... 

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