Sodium p-nitrobenzoate

Method 2. Ethyl p-nitrobenzoate. Place 21 g. of p-nitrobenzoic acid (Section IV,154), 11-5 g. of absolute ethyl alcohol, 3 8 g. of concentrated sulphuric acid, and 30 ml. of sodium-dried A.R. benzene in a 250 ml. round-bottomed flask, fit a reflux condenser, and heat the mixture under reflux for 16 hours. Add 50 ml. of ether to the cold reaction mixture, wash the extract successively with sodium bicarbonate soiution and water, dry with anhydrous magnesium sulphate or calcium chloride, and distil off the solvent on a water bath. Remove the last traces of benzene either by heating in an open evaporating dish on a water bath or in a bath at 100-110°. The residual ethyl p-nitrobenzoate (21 g.) solidifies completely on cooling and melts at 56°. 

Procedure Cholinesterase activity was measured according to the modified biochemical methods developed for crude preparations (Gorunef ah, 1978), using Ellman reagent 5,5"-dithio-bis(p-nitrobenzoic acid) or its red analogue 2,2-dithio-bis-(p-phenyleneazo)-bis-(l-oxy-8-chlorine-3,6) -disulfur acid in the form of sodium salt, which interact with thiocholine salt (Roshchina 2001). Water extracts of vegetative microspores of horsetail (Equisetum arvense) or Hippeastrum hybridum microspores (150 mg of microspores in 30 ml for 1 h) were used. 

The reduction to produce azoxy compounds appears to be successful for a wide range of aromatic nitro compounds. The following compounds, however, could not be reduced 1-nitronaphthalene, m-dinitrobenzene, 3,5-dinitroben-zoic acid (although o-, m-, and p-nitrobenzoic acids were reduced smoothly), compounds containing an amino group o-, orp- to a nitro group (except sodium... 

An exception to the generalized behavior in the anhydro-ring opening of furanosides is found in the reaction of methyl 2,3-anhydro-jS-n-lyxo-furanoside with sodium a-toluenethioxide.60 Surprisingly, predominant attack occurs at C-2, resulting in a 3 2 ratio of the 2-S-benzyl-2-thio- and 3-S-benzyl-3-thio-pentosides (isolated as the crystalline p-nitrobenzoates). 

The synthesis of bisalkynyl benzoates from bisalkynyliodonium triflates with sodium benzoate or p-nitrobenzoate in dichloromethane has also been reported (equation 89)43. The bisalkynyl esters are sensitive to hydration of the triple bonds, especially in solution, and have been isolated only in low yields. When R = H, monobenzoate derivatives are also obtained. 

Many organic acids, bases, and salts can act as depolarizers when ions are discharged which react easily with them. For example, p-nitrobenzoic acid in alkaline solution is reduced smoothly to p-azobenzoic acid. The sodium ions which are discharged react so rapidly with the nitro-group that the nitrobenzoic acid does not behave as an electrolyte but essentially as a depolarizer, particularly since the ions of the sodium... 

Free 4-thio-L-ribofuranose (247) is formed as a chromatographically homogeneous syrup on controlled deacetylation of the tetraacetate 246 with sodium methoxide. The absence of infrared absorption at 5.75 and 3.90 pm distinctly points to a thiofiiranoid ring. A crystalline tetrakis(p-nitrobenzoate) (251) of 4-thio-j8-L-ribofuranose was obtained on treatment of 247 with p-nitrobenzoyl chloride in pyridine ... 

Very few well-documented cases of intramolecular rDA reactions are known that occur during solvolysis. Three examples that exist are the aqueous ethanolysis of (241) in excess sodium cyanide (equation 105), the hydrolysis of a related p-nitrobenzoate in aqueous acetone, ° and a related tosylate in TFA. In each case a cyclopentadienyl derivative is formed by an intramolecular rDA process, which can then be trapped as a DA adduct, tautomerize or dimerize. 

The past few years have witnessed a considerable effort by several research groups to effect stereoselective syntheses of appropriately substituted hydroazulenes. Recently some new approaches to this problem have been reported. Marshall and Huffman, for instance, have found that treatment of the enone-mesylate (395) with diborane followed by base-induced fragmentation of the intermediate boronate (396) yielded the cyclodecadienol (397) in 60 % yield. Solvolysis of the p-nitrobenzoate of (397) in aqueous dioxan containing sodium bicarbonate afforded the hydroazulenol (398) in 70 % yield. The high degree of stereoselectivity in this reaction is rationalized on the basis of the preferred mode of cyclization of the allylic cation (399). To date, the solvolytic routes to hydroazulenes have... 

Reduction of the hemialdal (11) or its hydrate with sodium borohy-dride or potassium borohydride gave the corresponding diprimary alcohol (22), characterized as its diacetate, di-p-nitrobenzoate, and... 

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