Powder amino preparation

Amino-2-hydroxybenZOiC acid. This derivative (18) more commonly known as 4-aminosa1icy1ic acid, forms white crystals from ethanol, melts with effervescence and darkens on exposure to light and air. A reddish-brown crystalline powder is obtained on recrystallization from ethanol —diethyl ether. The compound is soluble ia dilute solutioas of nitric acid and sodium hydroxide, ethanol, and acetone slightly soluble in water and diethyl ether and virtually insoluble in benzene, chloroform or carbon tetrachloride. It is unstable in aqueous solution and decarboxylates to form 3-amiaophenol. Because of the instabihty of the free acid, it is usually prepared as the hydrochloride salt, mp 224 °C (dec), dissociation constant p 3.25. 

Paraformaldehyde [30525-89-4] is a mixture of polyoxymethylene glycols, H0(CH20) H, with n from 8 to as much as 100. It is commercially available as a powder (95%) and as flake (91%). The remainder is a mixture of water and methanol. Paraformaldehyde is an unstable polymer that easily regenerates formaldehyde in solution. Under alkaline conditions, the chains depolymerize from the ends, whereas in acid solution the chains are randomly cleaved (17). Paraformaldehyde is often used when the presence of a large amount of water should be avoided as in the preparation of alkylated amino resins for coatings. Formaldehyde may also exist in the form of the cycHc trimer trioxane [110-88-3]. This is a fairly stable compound that does not easily release formaldehyde, hence it is not used as a source of formaldehyde for making amino resins. 

This starting material can be prepared as follows, 123 parts of finely powdered 6-amino-2,4-dimethylpyrimidine are suspended in 250 parts of dry pyridine and 222 parts of p-nitroben-zenesulfonyl chloride added at 50°C to 55°C. The whole is then warmed for 2 hours to 55°C, Water is added to the crystalline aggregate obtained, the precipitated bis-N-(p-nitrobenzene-sulfonyl)-6-amino-2,4-dimethylpyrimidine filtered off by suction and washed with water. It is purified by recrystallizing from methyl ethyl ketone. On slowly heating it decomposes on rapidly heating it melts at about 210°C to 215°C with decomposition. 

Preparation of 2 -Amino-6 -diethylaminofluoran (74a). A mixture of 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid (0.1 mol), p-anisidine (0.1 mol), and concentrated sulfuric acid (100 g) was stirred at 50 °C for 24 h. After being cooled, the mixture was poured into water (500 ml), and made alkaline by 20% aqueous sodium hydroxide. The precipitate was filtered off, washed with water, dried, and then recrystallized from toluene to give 2 -amino-6 -diethylaminofluoran in 90% yield as an off-white powder, mp 213-215 °C. 

Simultaneously with Hansa Yellow G, compound 84 was first described as early as 1909 by Farbenfabriken Bayer. Its preparation starts from l-amino-4-bro-moanthraquinone-2-sulfonic acid (bromamine acid) 85. Dimerization is achieved through the Ullmann reaction, i.e., treatment with fine-grain copper powder in dilute sulfuric acid at 75°C. The separated intermediate, the disodium salt of 4,4 -diamino-l,l -dianthraquinonyl-3,3 -disulfonic acid 86, is heated to 135 to 140°C in the presence of 80% sulfuric acid in order to cleave the sulfonic acid groups [7] ... 

Culture medium is typically prepared by addition of the base powder or liquid concentrate mixtures to appropriate grade water. These base media mixtures usually contain amino acids, vitamins, cell membrane precursors, antioxidants, and growth factors, to mention some major categories of nutrients. Additional components, such as proteins or lipids, may need to be added separately since they are usually not compatible in powder blends. 

As a starting material for the preparation of sym-trinitrotriazidobenzene, 1,3,5-trichlorobenzene is used. It is obtained by the chlorination of aniline and the removal of the amino group. Nitration to the trinitro derivative is described in Vol. I. The final reaction is simple powdered 1,3,5,-trichloro-2,4,6-trinitrobenzene is added to an aqueous alcohol solution of sodium azide. The precipitated product is washed with alcohol and water and dried at a moderate temperature. The product so obtained may be purified by crystallization from chloroform. 

Suitable material is available from Pfanstiehl Laboratories, Waukegan, Illinois. It may also be prepared from the hydrochloride of 2-amino-2-deoxy-D-glucose (D-glucosamine) in 95% yield by the facile procedure of Inouye and co-workers.2 The 2-acetamido-2-deoxy-D-glucose should be dried at 25° (1 mm.) for at least 12 hours before use. If this material is in the form of a powder rather than compact crystals, more acetyl chloride... 

Substance P and neurokinin 1 receptors. The first neurokinin was discovered in the 1930s in extracts of brain or intestine. Since it was prepared as a powder, it was called substance P. This molecule is now known to be a string of 11 amino acids (an undecapeptide) (Fig. 5—67). This is in sharp contrast to monoamine neurotransmitters, which are modifications of a single amino acid. 

We have been unsuccessful in preparing this 1 1 cocrystal of 2,5-diaminopyrimidine and 2-amino-5-nitropyrimidine from solution but we have prepared a 1 1 cocrystal of the two components by solid-state grinding and heating. Neither the crystal structure nor the hydrogen-bond pattern is known at this point, but the X-ray powder pattern of the cocrystal product is distinctly different from those of the starting materials. 

Cognate preparations. 2-Amino-S-iodotoluene. Triturate 20 g (0.14 mol) of dry o-toluidine hydrochloride and 35.5 g (0.14 mol) of powdered iodine in a mortar and then grind in 17.5 g of precipitated calcium carbonate. Transfer the mixture to a conical flask, and add 100 ml of distilled water with vigorous shaking of the flask. Allow the mixture to stand for 45 minutes with occasional agitation, then heat gradually to 60-70 °C for 5 minutes, and cool. Transfer the contents of the flask to a separatory funnel, extract the amine with three 80 ml portions of ether, dry the extract with anhydrous calcium chloride or magnesium sulphate and remove the excess of solvent. The crude 2-amino-5-iodotoluene separates in dark crystals. Recrystallise from 50 per cent alcohol nearly white crystals, m.p. 87 °C, are obtained, 26 g (80%). 

Final proof for the inferred structure (1) for cyclosporin A and a first insight in the shape of the molecule resulted from X-ray analysis and high-resolution NMR spectra. The preparation of a crystallized derivative containing a heavy atom was achieved by an addition reaction using iodine and thallium(I) acetate. Instead of the expected iodoacetoxy derivative, the cyclic product (11) was obtained. Obviously, the reaction proceeded by a selective addition of iodine to the double bond of the MeBmt unit followed by an internal cyclization with the participation of the OH group. Iodocyclosporin A (11) reverted easily with Zn powder in acetic acid into genuine cyclosporin A by rranr-elimination. X-ray analysis [6] revealed that iodocyclosporin A assumes a rather rigid backbone conformation. The amino acids 1-6 adopt an antiparallel, markedly twisted /i-pleated sheet conformation, whereas the residues 7-11 form a loop. 

Such small particles usually are generated by air-jet micronization and less frequently by controlled precipitation or spray drying. As bulk powder, they usually tend to be very cohesive and exhibit poor flow and insufficient dispersion because of large interparticle forces such as van der Waals and electrostatic forces (Zeng et al. 2001 Podczeck 1998 Hickey et al. 1994). The control of sufficient powder flow and deaggregation (dispersion) is thus of utmost importance to ensure efficient therapy with a dry-powder aerosol. Two different formulation approaches are used currently in marketed DPI preparations to fulfill the requirements. Most often, coarse particles of a pharmacologically inactive excipient, usually a-lactose monohydrate, are added that act as a carrier and provide sufficient powder flow to the mixture. Other carbohydrates, amino acids, and phospholipids have been suggested frequently (Crowder et al. 2001). 

The isolated proteinaceous surfactants, obtained from commercial agarose powder and forest soil extract, were found to have extremely similar total amino acid compositions. Table 4.2 summarizes the amino acid values obtained from four determinations for each of the two surfactant preparations it can be seen that the rather unusual amino acid ratios obtained (among 17 different amino acids) for the two separate cases closely resemble one another. Specifically, in both of these cases the relative amounts of the different amino acids identified (excluding tryptophan which is completely destroyed during acid hydrolysis) were as follows glycine serine > aspartic acid (and/or aspara-... 

Reaction of 4-(hydroxyl methylphosphinyl)butanoic acid (154) with thionyl chloride followed by successive treatment with copper powder, potassium iodide, and potassium carbonate affords l-methyl-2-oxophospholane 1-oxide (155) in 65% yield. 3-Bromo-, 3-amino-, 3-acethylamino-l-methyl-2-oxophospholanes (156-158) are prepared by substitution of the 3-methylene position (Scheme 51) [64]. 

Most mono-anchor dyes are derivatives of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine [108-77-0]), a molecule of wide synthetic potential because the three chlorine atoms on the triazine ring differ in their reactivities [12], The first chlorine atom exchanges with nucleophiles in water at 0 - 5 °C, the second at 35 -40 °C, and the third at 80 - 85 °C. A wide variety of triazinyl dyes can thus be prepared by careful selection of the reaction conditions. Condensation of cyanuric chloride with a chromophore ( Chrom. ) containing an amino group yields the highly reactive dichlorotriazinyl dyes 1 [11]. These very reactive dyes are sensitive to hydrolysis, and a suitable buffer is usually added to the powdered dye to increase its stability [13],... 

The synthesis of the 1 1 complex 8 is an example of [10] demethylative chroma-tion. It is prepared by diazotization of 5-amino-2-chlorohydroquinone dimethyl ether and coupling onto 1-hydroxynaphthalene-5-sulfonic acid. The reaction product and Cr203 in formic acid are heated in an autoclave at 130 °C. The chromium complex 8 [80004-31-5] is obtained as a black powder that gives grayish blue dyeings on wool and leather. 

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