Derivatives Dinitrobenzoates

The conversion of the compounds under investigation into coloured derivatives (e.g., the separation of carbonyl compounds by conversion into their 2 4-dinitrophenylhydrazones, etc. of hydrocarbons through their picrates of alcohols through their 3 5-dinitrobenzoates of glucose, fructose and other simple sugars through their p-phenylazobenzoyl esters). 

The experimental procedure to be followed depends upon the products of hydrolysis. If the alcohol and aldehyde are both soluble in water, the reaction product is divided into two parts. One portion is used for the characterisation of the aldehyde by the preparation of a suitable derivative e.g., the 2 4-dinitrophenylhydrazone, semicarbazone or di-medone compound—see Sections 111,70 and 111,74). The other portion is employed for the preparation of a 3 5-dinitrobenzoate, etc. (see Section 111,27) it is advisable first to concentrate the alcohol by dis tillation or to attempt to salt out the alcohol by the addition of solid potassium carbonate. If one of the hydrolysis products is insoluble in the reaction mixture, it is separated and characterised. If both the aldehyde and the alcohol are insoluble, they are removed from the aqueous layer separation is generally most simply effected with sodium bisulphite solution (compare Section Ill,74),but fractional distillation may sometimes be employed. 

Dissolve 2 drops of concentrated sulphuric acid in 2 ml. of the ester and add 1 - 5 g. of 3 5-dinitrobenzoic acid. If the b.p. of the ester is below 150°, refiux the mixture gently if the b.p. is above 150° heat the mixture, with frequent shaking at first, in an oil bath at about 150°. If the 3 5-dinitrobenzoic acid dissolves within 15 minutes, heat the mixture for 30 minutes, otherwise 60 minutes heating is required. Allow the reaction mixture to cool, dissolve it in 25 ml. of ether, and extract thoroughly with 5 per cent, sodium carbonate solution (ca. 25 ml.). Wash the ethereal solution with water, and remove the ether. Dissolve the residue (which is usually an oil) in 5 ml. of hot alcohol, add hot water cautiously until the 3 5-dinitrobenzoate commences to separate, cool and stir. Recrystallise the derivative from dilute alcohol the yield is... 

Irradiated ergosterol was found not to be as antirachitic in the chick as in the rat, whereas the chick could be protected by direct kradiation. The provitamin in cholesterol was shown not to be ergosterol. Rygh (14) in 1935 found that 1 rat unit of cod Hver oil was 100 times more potent in chicks than 1 rat unit of vitamin D2. Brockmann (15) in 1936, prepared the pure crystalline 3,5-dinitrobenzoate derivative of vitamin D obtained from tuna Hver oil... 

Rhodamine B vaseline [155] diphenyl, polyphenols [156] maleic and fu-maric acids [162] flavonoids [158] alcohols as 3,5-dinitrobenzoates [159, 160] gangliosides [161] 1-hydroxychlorden [162] carbamate pestiddes [163] para-thion and its metabolites [164] polyethylene and polypropylene glycols [165] terpene derivatives [166] menthol [167]... 

Some substrates like benzoic acid, benzaldehyde etc. are so deactivated that direct nitration to their trinitro derivatives is not possible. Direct nitration of benzoic acid with excess fuming nitric and concentrated sulfuric acids at a temperature of 145 °C for several hours results in the formation of 3,5-dinitrobenzoic acid (54-58 %). The use of oleum in such reactions can significantly reduce the rate of nitration due to carbonyl protonation (see Section 4.3.3). Consequently, indirect routes are used for the synthesis of polynitroarylenes like 2,4,6-trinitrobenzoic acid and 2,4,6-trinitrobenzaldehyde (Section 4.9). 

In the event, osmylation of compound 16 in pyridine, followed by the usual workup, afforded a 92% yield of an 18 1 mixture of two diols. That the major one, mp 136-139° C, has the stereochemistry implied in 20 need not be debated in light of a single crystal determination of its 7,8-bis-3,5-dinitrobenzoate derivative 21, mp 114.5-115.5° C (see Figure 5). ... 

TABLE 10.21 Direct Mutagenicities of Two Nitroazabenzo[a]pyrenes, Their N-Oxide Derivatives,u and 3,6-Dinitrobenzo[a]pyrenec Detected in Ambient and Diesel Particulate Matter15 and, for Comparison, l- and 3-Nitrobenzotalpyrene... 

Figure 6.4 Monitoring of electroosmosis stability during separation of derivatives of benzoic acid using a thermo-marker. TMl—first thermo-marker, TM2—second thermo-marker 1—aminobenzoic acid, 2— benzoic acid, 3—3,5-dihydroxybenzoic acid, 4—salicylic acid, 5—3,5-dinitrobenzoic acid. Background electrolyte 5 mM [C4CiIm][FAcO] in acetonitrile.

Dinitrobenzoates. The following experimental details are for glycine (aminoacetic acid) and may be easily adapted for any other amino acid. Dissolve 0-75 g. of glycine in 20 ml. of N sodium hydroxide solution and add 2 32 g. of finely powdered 3 5-dinitrobenzoyl chloride. Shake the mixture vigorously in a stoppered test-tube the acid chloride soon dissolves. Continue the shaking for 2 minutes, filter (if necessary) and acidify with dilute hydrochloric acid to Congo red. Recrystallise the derivative immediately from water or 50 per cent, alcohol. 

Ethyl p-aminobenzoate and derivs 6 E203 ethyl p-amino-dinitrobenzoates 6 E203 ethyl p-aminonitrobenzoates 6 E203... 

Ethylidene acetobenzoate and derivs 6 E302 ethylidene aceto-3,5-dinitrobenzoate 6 E302... 

Fluorobenzoic acid and derivs 6 FI37 2-fluoro-4,5-dinitrobenzoic acid 6 F137 2-fluoro-4-nitrobenzoic acid 6 FI 37... 

Alcohols, prior to the separation by means of paper or thin layer chromatography, must be converted into suitable derivatives, mostly into 3,5-dinitrobenzoic acid esters or into the acid semiesters of 3-nitrophthalic acid or diphenic acid. The direct re-esterification of ester plasticizers with 3,5-dinitrobenzoic acid is applicable to plasticizer analysis (7). 

Cyclocondensation of 2-aminopyridines and methyl 2-chloro-3,5-dinitrobenzoate in boiling ethanol in the presence of sodium acetate for 12 h gave 8,10-dinitro-6//-pyrido[l,2-a]quinazolin-6-ones (312) [96JAP(K)96/157476]. 6//-Pyrido[l,2-a]quinazoline derivatives were prepared in the reaction of 2-aminopyridine and salicylaldehydes followed by treatment with NaBH4 (93MI7). 

Nitration of benzo[6Jselenophene under mild conditions (HNO3/HOAc/20 °C) yields 35% of the 3-nitro derivative and 5% of 2-nitrobenzo[Z>]selenophene, while under more vigorous conditions (HNO3/HOAC/H2SO4/7O °C) 27% of 2,3-dinitrobenzo[6]selenophene was obtained (77BSF157). 

Nitrenium ions can also be generated by solvolyzing esters of N,N-di-alkylhydroxylamines. 3,5-Dinitrobenzoates (129) were found to be the most useful hydroxylamine derivatives.171... 

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