Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Picryl derivatives

The presence of three nitro groups on the aromatic ring of picryl chloride makes the chloro group extremely reactive towards nucleophiles. Picryl chloride (87) is hydrolyzed to picric acid (4) in the presence of hot water or aqueous sodium hydroxide. Aminolysis of picryl chloride in the presence of primary and secondary amines is complete in minutes at room temperature. Picryl chloride is therefore a very useful starting material for the synthesis of a range of other picryl derivatives. The reaction of picryl chloride (87) with ammonia can be used to synthesize 2,4,6-trinitroaniline (53) (picramide). Treatment of picryl chloride with alcohols under reflux forms picric acid and the alkyl chloride of the corresponding alcohol, whereas the same reaction in the presence of alkali metal hydroxides, or the alkoxide anion of... [Pg.158]

Only activated aryl halides (e.g. 2,4-dinitrochlorobenzene and picryl chloride) react with pyridine, and the facility of these reactions is subject to much the same steric and electronic controls as alkylation. Picryl chloride forms characteristic yellow TV-picryl derivatives with pyridines. These have been used to help separate, purify and characterize particular liquid pyridines. Pyridine also undergoes quaternization with diphenyliodonium fluoroborate (equation 19). Treatment of pyridine 1-oxides with arenediazonium salts yields aryloxy quaternary salts (equation 20). [Pg.179]

If the A-aryl group is strongly activated, then it can be removed in nucleophilic substitution reactions in which the azole anion acts as leaving group. Thus l-(2,4-dinitrophenyl)-pyrazole and -imidazole react with N2H4 or NaOMe. Their A-picryl derivatives react similarly with BuNIT or water at a range of pH values. [Pg.593]

Nitro-l,2,4-triazole-5-one picryl derivatives, amine salts... [Pg.420]

Nitro-2-picryltetrazole can be prepared by the reaction of picrylchloride with sodium salt of nitrotetrazole in acetone. When water is present, picric acid is formed, casting doubts on the hydrolytic stability of the picryl derivative [4]. [Pg.222]

The benzo analogue 684 of [1,2,4]triazino[3,2-6]thiazoles was prepared (88LA1089) by heating triazine derivative 632 with 2,4-dinitrochloroben-zene or picryl chloride in N,N-dimethyl formamide (Scheme 143). [Pg.123]

Activating agents, such as trifluoroacetic anhydride 1,1 -carbonyldiimidazolc carbodiimides sulfonyl, tosyl, and picryl chlorides and a range of phosphorus derivatives can promote direct solution reactions between dicarboxylic acids and diols or diphenols in mild conditions. The activating agents are consumed during the reaction and, therefore, do not act as catalysts. These so-called direct polycondensation or activation polycondensation reactions proceed via the in situ transformation of one of the reactants, generally the carboxylic acid, into a more... [Pg.77]

The harsh conditions needed to introduce five or more nitro groups into diphenyl ether lead to the destruction of the aromatic ring. Highly nitrated derivatives of diphenyl ether can be prepared by an indirect route 2,2, 4,4, 6-pentanitrodiphenyl ether (92) is the product from the controlled nitration of (91), which is obtained from the reaction of picryl chloride (87) with sodium o-nitrophenolate. ... [Pg.160]

The conjugation in 2,2, 4,4, 6,6 -hexanitroazobenzene (HNAB) (90) is also reflected in its thermal stability (m.p. 220 °C). The synthesis of HNAB from picryl chloride and 2,4-dinitrochlorobenzene is discussed in Sections 4.8.1.2 and 4.8.1.3 respectively. 3,3, 5,5 -Tetraamino-2,2, 4,4, 6,6 -hexanitroazobenzene (149) has been synthesized by an unusual but efficient route which involves the nitration-oxidative coupling of 3,5-dichloroaniline (147) on treatment with nitric acid, followed by reaction of the resulting product, 3,3, 5,5 -tetrachloro-2,2, 4,4, 6,6 -hexanitroazobenzene (148), with ammonia. Both the tetrachloro (148) and tetraamino (149) derivatives exhibit high thermal stability. [Pg.177]

Also called 2,6-Dinitro-4-Picrylaminephenol in Ger). (O, N)3C6H2NHC6H2(N02)20H mw 410.22, N 20.49%, OB to C02 -62.4% ochre-yel crystals (from HAc), mp 248° insol in water, si sol in ale sol in alkalis with formation of a deep-brown color. Prepd by heating picryl chloride, isopicraminic acid NaAc in aq ale. No explosive props are mentioned for it nor for the tetranitro derivatives (Ref 2). The Na salt, of the pentanitro derivative NaCi2HsOuN6, red platelets, explodes above 300°. The 3 -Hydroxy-4-methyl-pentanitro diphenylamine is not explosive (Ref 3)... [Pg.240]

Subsequently, Tselinskii et al. found the dianion of Compound 2a to be stable and reacted it with a variety of electrophiles including picryl chloride, acetic anhydride, methyl iodide and vinyl ketone. They synthesized its dinitro derivative, dinitrodifurazano piperazine (2b) (DNDFP) [Structure (2.63)] by reacting the dianion (2a) with nitrogen oxide in CH3CN. The dinitro derivative which is quite reactive, was isolated by column chromatography and confirmed by mass spectroscopy [272]. [Pg.140]

Methylnitramine decomposes explosively in contact with concentrated sulphuric acid. It is evolved when aniline reacts with tetryl, a diphenylamine derivative (p. 51) is produced simultaneously. Methylnitramine reacts with picryl chloride to form tetryl. The structure of tetryl (p. 40) was first proved by this synthesis. [Pg.16]

The organic derivatives of hydrazoic acid which contain an aromatic ring with nitro groups comprise an important group of initiators. Picryl azide (VII), m.p. 89-90°C is a typical example. It has been prepared both by the action of nitrous acid on trinitrophenylhydrazine (Purgotti [154], Schrader [155] and Korczynski [156]) and by the action of sodium azide on picryl chloride. Rathsburg [157] suggested... [Pg.192]

Azo derivatives of indolizines are readily prepared since the arenediazonium ion is a good electrophile. Compounds of this type are sometimes used as dyes (73AC(R)95>. Another method of preparing azobisindolizines is by reaction of indolizines with tosyl or picryl azides thus compound (33) has been obtained from 2-methylindolizine by this route. Redox characteristics of such compounds have been studied (71LA(752)182, 71LA(752)196). [Pg.455]

Chloropicryl Chloride See Chloride Salt of TNCB(or Picryl Chloride) under Chlorobenzene and Derivatives... [Pg.47]

N 18.06% yel ndls, mp 108° readily sol in benz, chlf acet mod sol in ale insol in w was prepd by boiling picryl chloride in ale with 45% aq cyclohexylamine. Nitration yields a more expl deriv... [Pg.383]

Indolizines also react readily with activated halides such as picryl chloride146 and tricyanovinyl chloride147 to form highly colored derivatives. [Pg.134]

A wide range of organic azides such as alkyl,80 alkenyl,79,100 aryl, including dinitrophenyl and picryl,101-103 heterocyclic,28,91 trimethylsilyl,79,104 acyl,9 phosphoryl,105 sulfonyl,106 alkoxycarbonyl,9 and oxime azides107 has been found to add to norbornene,25,79,90,104,105,107-121 its derivatives,104 106,1 13,120,122-128 or to related bridged bicyclic... [Pg.227]

The reactions of picryl fluoride with (2,3-dihydroxypropyl)-ammonium or -phosphonium compounds have been found120 to yield zwitterionic spiro-cr-adducts such as (31). Aromatic diazonium cations have been shown to add to the 9-position of cr-adducts of 9-nitroanthracene to yield neutral derivatives.121 A study has been reported of the effects of ion pairing and change of solvent on the kinetics of decomposition of some anionic cr-adducts.122... [Pg.253]

Picramide and its N-substituted derivatives introduce the added complication that proton loss may occur from the amino-group to give the Bronsted bases 23 (R = H, alkyl, phenyl). Green and Rowe (1913) found support for this formula from the alkali metal analyses of the solids formed from many polynitroanilines with bases. In fact picramide itself has been frequently used as an indicator for establishing H-acidity scales in basic media on the assumption that its indicator behaviour is due to proton loss (Schaal, 1955 Stewart and O Donnell, 1962 Stewart et al., 1962). The most likely other alternatives for the products of 1 1 interaction of picramides with bases are 24 and 25 (R = H, alkyl, phenyl R =R = H, alkyl). Formula 24, the analogue of Meisenheimer s formula for the adducts of picryl ethers, was suggested by Busch and... [Pg.227]


See other pages where Picryl derivatives is mentioned: [Pg.302]    [Pg.53]    [Pg.757]    [Pg.217]    [Pg.758]    [Pg.161]    [Pg.302]    [Pg.53]    [Pg.757]    [Pg.217]    [Pg.758]    [Pg.161]    [Pg.7]    [Pg.195]    [Pg.864]    [Pg.382]    [Pg.126]    [Pg.250]    [Pg.110]    [Pg.233]    [Pg.656]    [Pg.383]    [Pg.400]    [Pg.200]    [Pg.260]    [Pg.45]    [Pg.202]    [Pg.329]    [Pg.201]    [Pg.200]   
See also in sourсe #XX -- [ Pg.53 ]




SEARCH



© 2024 chempedia.info