Picramates

Amino-4,6-dinitrophenol. This derivative (10), also known as picramic acid, forms dark red needles from ethanol and prisms from... 

The compound can be prepared from 2,4,6-trinitrophenol (picric acid [88-89-1]) by reduction with sodium hydrosulfide (163), with ammonia —hydrogen sulfide followed by acetic acid neutralization of the ammonium salt (164), with ethanolic hydrazine and copper (165), or electrolyticaHy with vanadium sulfate in alcoholic sulfuric acid (159). Heating 4,6-dinitro-2-benzamidophenol in concentrated HQ. at 140°C also yields picramic acid (166). 

The first synthetic dyestuff, mauveine, was discovered by Perkin in 1856 in the UK and led to many investigations of the derivatives of coal tar as potential coloring matters. The first dia2onium salt derived from picramic acid was prepared in 1858 and is still the basic chemistry behind coundess commercial products. Despite these inventions, in 1900 the vast majority of dyestuffs were still of natural origin. Now at the end of the century the situation has changed dramatically synthetic dyes dominate. 

Picramates. Salts of Picramic Acid. See in Vol 1, A242-Lto A243-L... 

Picramic Acid. See under 4,6-Dimtro-2-amino-phenol in Vol 1, A241-R... 

C6H2(N02)30H (NH SaQs C02+HN03+HCN When mildly reduced, for example with Na sulfide or hydrosulfite or with ferrous sulfate, PA is converted into picramic acid, a very useful intermediate in the dyestuffs industry and a starting material for the preparation of Diazo-dinitrophenol, a primary expl (see Vol 2, B59-L). Stronger reduction may lead to the formation of triamino phenol... 

The fact that practically all aromatic amines are readily converted into diazo compounds contributed greatly to Griess s success. The original method (Griess, 1858) by which he diazotized picramic acid (1.1 see Scheme 1-1) consisted of passing nitrous gases, prepared by the reduction of nitric acid with starch or arsenious acid, into an alcoholic solution of the amine. 

Bangor Naval Submarine Base Recreational fishing Fish and shellfish consumption TNT RDX Picric acidc Picramic acidc... 

Originally prepared in 1858 by Griess, it is made by diazotising picramic acid with sodium nitrite and hydrochloric acid according to the following reaction ... 

This partially reduced derivative of picric acid, picramic acid , explodes very powerfully when dry. 

Agrawal, J. P. etal., Propellants, Explos., 1981, 6, 112-116 The picramate is less stable than the picrate. 

Shortly after Perkin had produced the first commercially successful dyestuff, a discovery was made which led to what is now the dominant chemical class of dyestuffs, the azo dyes. This development stemmed from the work of Peter Griess, who in 1858 passed nitrous fumes (which correspond to the formula N203) into a cold alcoholic solution of 2-aminO 4,6 dinitrophenol (picramic acid) and isolated a cationic product, the properties of which showed it to be a member of a new class of compounds [1]. Griess extended his investigations to other primary aromatic amines and showed his reaction to be generally applicable. He named the products diazo compounds and the reaction came to be known as the diazotisation reaction. This reaction can be represented most simply by Scheme 4.1, in which HX stands for a strong monobasic acid and Ar is any aromatic or heteroaromatic nucleus. 

Cl Sulphur Black 1, which is produced from the relatively simple intermediate 2,4-dinitrophenol and aqueous sodium polysulphide. A similar product (Cl Sulphur Black 2) is obtained from a mixture of 2,4-dinitrophenol and either picric acid (6.148 X = N02) or picramic acid (6.148 X = NH2). A black dye possessing superior fastness to chlorine when on the fibre (Cl Sulphur Black 11) can be made from the naphthalene intermediate 6.149 by heating it in a solution of sodium polysulphide in butanol. An equivalent reaction using the carbazole intermediate 6.150 gives rise to the reddish blue Cl Vat Blue 43 (Hydron blue). This important compound, which also possesses superior fastness properties, is classified as a sulphurised vat dye because it is normally applied from an alkaline sodium dithionite bath. Interestingly, inclusion of copper(II) sulphate in the sulphurisation of intermediate 6.150 leads to the formation of the bluish black Cl Sulphur Black 4. 

Cobalt(II) picramate, 3460 Copper(I) chloroacetylide, 1354 Diacetatotetraaquocobalt, 1780 Dicopper(I) ketenide, 0621... 

Explosive properties of palladium(II) and uranyl picramates were determined. 

Trimethyldecahydroquinolinium picrate, 3765 Ammonium picrate, 2322 Calcium picrate, 3430 Cobalt(II) picramate, 3460 Copper(II) picrate, 3432 Lanthanum picrate, 3741 Lead(II) picrate, 3436 Manganese picrate hydroxide, 3742 Mercury(II) picrate, 3433 S-7-Methylnonylthiouronium picrate, 3737 Nickel picrate, 3435 Potassium picrate, 2085 Sodium picrate, 2086 Zinc picrate, 3437... 

Cobalt(II) picramate, 3460 Copper(II) 3,5-dinitroanthranilate, 3627 Copper(II) picrate, 3432... 

Korenman, Yak, Nefedova, T.E., andByukova, R.I. Extraction of picramic acid, Int.J. Pharmacol. Ther. Toxicol, 51 734-735, 1977. 

Diazo-4,6-dinitrophenol (DDNP or DINOL) (53) can be prepared from the diazotization of 2-amino-4,6-dinitrophenol (52) (picramic acid) with nitrous acid " the latter is obtained from the selective reduction of picric acid with ammonium sulfide." 2-Diazo-4,6-dinitrophenol (53) is widely used as an initiating charge in detonators and caps. 

Explosive properties of palladimn(ll) and manyl picramates were determined. 

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