Phosphoric acid mixed

Nitric Acid. —2 cc. of phosphoric acid mixed with 2 cc. of concentrated sulphuric acid, and overlaid with 1 cc. of a solution of ferrous sulphate, must not develop a colored zone. 

Amino Acid-Phosphoric Acid Mixed Anhydrides. 100... 

Several systems based on the potentialities of amino acid-phosphoric acid mixed anhydrides have been devised to check the idea that the genetic code developed from an early pathway of RNA-dependent peptide synthesis in an RNA world [168]. RNA sequences have thus been selected that are capable of self-aminoacylation using amino acid adenylates, catalyzing a reaction chemically similar to the aminoacylation of fRNA by the protein aminoacyl fRNA synthetases [169]. 

Phosphorus was first isolated in the seventeenth century by a procedure, which gave a recovery of about one ounce of phosphorus from a hogshead (large barrel, ca. 238 L) of urine [8]. In 1769, a more convenient method that made larger quantities accessible was developed by Scheele. This involved treating crushed bones with sulfuric acid and extraction of the phosphoric acid from the gypsum with small amounts of water. The water was then evaporated and the residual phosphoric acid mixed with charcoal, and then vigorously heated (Eqs. 10.2 and 10.3). 

Intermediate 113 was transformed into the trimethylsilyl methyl ketone 119 in quantitative yield via the acid chloride, followed by the addition of trimethylsilylmethyl lithium (Scheme 2.13). Subsequent Peterson olefination of aldehyde 108 with 119 resulted in the required unsaturated ketone 120 in 95% yield. Subsequent desilylation and thioester hydrolysis afforded a 97% of the seco acid 121. Lactonization was achieved in 32% yield via the phosphoric acid-mixed anhydride, however this procedure also formed about 25% of the dimeric bis lactone. Following removal of the acetonide under the action of acid, a nonselective oxidation with RuCl2(Ph3P)3 produced a 1 1 mixture of the natural... 

Dilute Phosphoric Acid. Mix 5 troy ounces nitric acid with i pint distilled water in a porcelain capsule of the capacity of 2 pints add 6 drachms phosphorus and invert over it a glass funnel of such dimen-eiona that its rim may rest on the inside of the capsule, near the surface of the liquid. Place the capsolo on a sand-bath, and apply a moderate beat until the phosphorus is dia-isolved, and red vapors cease to rise. If the reaction becomes too violent, add a little distilled water and if tho red vapors cease to be evolved before the phospbora.s is all nitric acid (diluted as before) until the solution is effected. Remove... 

Masamune et al. [42] developed the macrolactonization of to-hydroxy r-butyl thioester with Hg(OCOCp3)2 in MeCN at room temperature, and this method accomplished the first total synthesis of methynolide [1]. They further developed an alternative method using a phosphoric acid mixed anhydride, which was apphed to the synthesis of narbonolide [43] and tylonolide [44]. 

Sample preparation Plasma. Condition a 3 mL 500 mg Bond Elut C8 SPE cartridge with 3 mL MeOH and 2 mL 1% phosphoric acid. 500 p,L Plasma -I- 1 mL 1% phosphoric acid, mix, add to the SPE cartridge, wash with 3 mL 1% perchloric acid, elute with 750 p.L MeOH, inject a 50 pL aliquot of the eluate. Sinus mucosa. Condition a 1 mL Bond Elut C8 SPE cartridge with 1 mL MeOH and 1 mL 1% phosphoric acid. Chop sample with a scalpel, weigh out 20 mg and add it to 500 xL 10 mM pH 7.0 phosphate huffer, rotate at 4° for 12 h, centrifuge at 800 g for 10 min. 400 p,L Supernatant -t- 1 mL 1% phosphoric acid ( ), mix, add to the SPE cartridge, wash with 1% perchloric acid, elute with 150 xL MeOH, inject a 75 jiL aliquot of the eluate. 

Sample preparation Condition a 3 mL 40 p,m bonded silica Clean Screen SPE cartridge (Worldwide Monitoring) with 3 mL MeOH, 3 mL water, and 1 mL pH 3 phosphate buffer. 1 mL Plasma + 2 mL 10 mM phosphoric acid, mix, add to the SPE cartridge, air dry for 30 s, wash with 1 mL pH 3 phosphate buffer, wash with 1 mL MeOH, air dry for 30 s, elute with 3 mL 2% ammoniacal MeOH. Evaporate the eluate to dryness under a stream of nitrogen at 45°, reconstitute the residue in 50 p,L mobile phase, inject an aliquot. 

Solvents 25 C Dichloroacetic acid (DCA), tri-fluoroacetic acid (TFA), phosphoric acid, mixed solvents containing TFA (4,5)... 

The biomimetic phosphoric acid mixed anhydride concept stimulated further search for activating reagents that produce derivatives of acylamino acids (and peptides) in more simple ways than the ones mentioned earlier in the Chapter (on p. 78) An interesting attempt in this direction is the so called Bates reagent [47] which on reaction with carboxylic acids yields acyloxyphosphonium salts. 

Cold mix plant for production of suspension mixtures Batch plant using liquid ammonia and phosphoric acid Mix plant for production of suspensions from granular MAP/DAP... 

Phosphoric acid, mixed decyl, octyl and ethyl esters 68412-60-2 3... 

Scheme 9.6. A cartoon representation of the enzyme (named glyceraldehyde-3-phosphate dehydrogenase, EC 1.2.1.12) catalyzed oxidation of the aldehyde glyceraldehyde-3-phosphate to the carboxylic acid-phosphoric acid mixed anhydride, 1,3-bisphosphoglycerate (which can be hydrolyzed to the corresponding carboxyhc acid and phosphoric acid). Start in a clockwise direction from the npper left.

Another sealant for smaller metal components consisted of phosphoric acid mixed with copper oxide. This would form thin even joint lines between flat surfaces of steel that were extremely difficult to separate. 

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