With -tartaric acid

Several structures of the transition state have been proposed (I. D. Williams, 1984 K. A. Jorgensen, 1987 E.J. Corey, 1990 C S. Takano, 1991). They are compatible with most data, such as the observed stereoselectivity, NMR measuiements (M.O. Finn, 1983), and X-ray structures of titanium complexes with tartaric acid derivatives (I.D. Williams, 1984). The models, e. g., Jorgensen s and Corey s, are, however, not compatible with each other. One may predict that there is no single dominant Sharpless transition state (as has been found in the similar case of the Wittig reaction see p. 29f.). 

The original commercial source of E was extraction from bovine adrenal glands (5). This was replaced by a synthetic route for E and NE (Eig. 1) similar to the original pubHshed route of synthesis (6). Eriedel-Crafts acylation of catechol [120-80-9] with chloroacetyl chloride yields chloroacetocatechol [99-40-1]. Displacement of the chlorine by methylamine yields the methylamine derivative, adrenalone [99-45-6] which on catalytic reduction yields (+)-epinephrine [329-65-7]. Substitution of ammonia for methylamine in the sequence yields the amino derivative noradrenalone [499-61-6] which on reduction yields (+)-norepinephrine [138-65-8]. The racemic compounds were resolved with (+)-tartaric acid to give the physiologically active (—)-enantiomers. The commercial synthesis of E and related compounds has been reviewed (27). The synthetic route for L-3,4-dihydroxyphenylalanine [59-92-7] (l-DOPA) has been described (28). 

Add calcium chloride and stir with a glass rod. A crystalline precipitate of calcium tartrate, C.,H40(,Cad-4H20, is formed u hich dissolves in acetic acid and caustic alkalis. Repeat the fniegoing test, but add a few drojts of acetic acid before the calcium chloride. There is no precipitate. Calcium sulphate also gives no precipitate with tartaric acid or neutial tartrates, ( compare reactions for OKalic acid, p. 100). 

The potassium (but not the sodium) salt is obtained by the obscure reaction of SO2 on aqueous thiosulfate. Aqueous solutions of the acid H2S30f, can then be obtained from K2S30f, by treatment with tartaric acid or perchloric acid. 

BE 613 545 (American Cyanamid appl. 6.2.1962 USA-prior. 23.1.1962). racemate resolution p/ (+)-2-aminobutanol with tartaric acid ... 

Brownson JRS, Georges C, Larramona G, Jacob A, Delatouche B, Levy-Clement C (2008) Chemistry of tin monosulfide (8-SnS) electrodeposition effects of pH and temperature with tartaric acid. J Electrochem Soc 155 D40-D46... 

Kwon, S.-M., Lee, K.-P., Tanaka, K., and Ohta, K., Simultaneous determination of anions and cations by ion-exclusion chromatography-cation-exchange chromatography with tartaric acid/18-crown-6 as eluent, /. Chromatogr. A, 850, 79, 1999. 

For the Ti(OiPr)4/silica system, the advantage of MCM-41 (a mesoporous silica) over an amorphous silica is not evident either in terms of activity or selectivity for the epoxidation of cyclohexene with H202 in tert-butyl-alcohol.148 Nevertheless, deactivation of the catalysts seems slower, although the selectivity of the recovered catalysts is also lower (allylic oxidation epoxidation = 1 1). Treatment of these solids with tartaric acid improves the properties of the Ti/silica system, but not of the Ti/MCM-41 system, although NMR,149 EXAFS,150 and IR151 data suggest that the same titanium species are present on both supports. 

Arsenic (V) causes large positive errors - arsenic (V) at a concentration of 10 pg/1 produces an absorbance of 0.07, but can be masked with tartaric acid (added in the reagent solution). When arsenic (V) was present at concentrations of 50 pg/1 it was masked with 0.1 ml of 1 x 10 4 M sodium thiosulfate added after the sulfuric acid. 

CdSe, CdTe. CdSe films have been grown from complexed (with tartaric acid and triethanolamine) cadmium acetate or cadmium sulfate solutions and sodium selenosullale.1272 81 84 The films were amorphous or nanocrystalline with an average crystallite size of 6nm. The optical band gap was 1.8-2.1 eV, and the electrical resistivity was of the order 104-106Qcm. 

Finely grind seeds (preferably woodrose) and add NaHC03. Extract with ethyl acetate by soaking about one day. Filter and extract the ethyl acetate with tartaric acid solution. Basify the extract with NaHCOj and extract it with ethyl acetate. Dry and evaporate in vacuum the ethyl acetate to get the alkaloids. Repeat this procedure on the seeds until no more residue is obtained. 

After a total of 24 days growth period the culture should be considered mature. Make the culture acidic with tartaric acid and homogenize in a blender for one hour. 

Reaction with chelating agents. Such reactions have been used primarily for partial dealumination of Y zeolites. In 1968, Kerr (8,21) reported the preparation of aluminum-deficient Y zeolites by extraction of aluminum from the framework with EDTA. Using this method, up to about 50 percent of the aluminum atoms was removed from the zeolite in the form of a water soluble chelate, without any appreciable loss in zeolite crystallinity. Later work (22) has shown that about 80 percent of framework aluminum can be removed with EDTA, while the zeolite maintains about 60 to 70 percent of its initial crystallinity. Beaumont and Barthomeuf (23-25) used acetylacetone and several amino-acid-derived chelating agents for the extraction of aluminum from Y zeolites. Dealumination of Y zeolites with tartaric acid has also been reported (26). A mechanism for the removal of framework aluminum by EDTA has been proposed by Kerr (8). It involves the hydrolysis of Si-O-Al bonds, similar to the scheme in Figure 1A, followed by formation of a soluble chelate between cationic, non-framework aluminum and EDTA. 

Surface modification of skeletal nickel with tartaric acid produced catalysts capable of enantiose-lective hydrogenation [85-89], The modification was carried out after the formation of the skeletal nickel catalyst and involved adsorption of tartaric acid on the surface of the nickel. Reaction conditions strongly influenced the enantioselectivity of the catalyst. Both Ni° and Ni2+ have been detected on the modified surface [89]. This technique has already been expanded to other modified skeletal catalysts for example, modification with oxazaborolidine compounds for reduction of ketones to chiral alcohols [90],... 

In fact, there are only two heterogeneous catalysts that reliably give high enantioselectivities (e.s. s) (90% e.e. or above). These are Raney nickel (or Ni/Si02) system modified with tartaric acid (TA) or alanine for hydrogenation of /(-kctocstcrs [12-30], and platinum-on-charcoal or platinum-on-alumina modified with cinchona alkaloids for the hydrogenation of a-ketoesters [31-73],... 

There are stability problems in urines stored for analysis. Fifty percent of delta-aminolevulinic acid was lost in specimens stored without preservative and exposed to light for 24 hours (V3). The loss increased to 80% in 48 hours, 85% in 72 hours, and 95% in 2 weeks. However, the same specimens acidified with tartaric acid and stored in the dark lost 2% of the aminolevulinic acid in 72 hours and 6% in 2 weeks (V3). The destruction of catecholamines collected in nonacidified urine specimens is well documented (Cll). Urinary acid phosphatase was destroyed on freezing (S15). The effect was related to increasing salt concentration during freezing and was prevented by the addition of albumin (S15). 

Y,A, -Dimethyl-l,2-bis[3-(trifluoromethyl)phenyl]-1,2-diaminocthanc, prepared in two steps from 3-trifluoromethylbenzaldehyde65, can be easily resolved with tartaric acid and reacted with aldehydes at room temperature to give imidazolidines. 

In view of this background, we developed a new chiral auxiliary to allow for the first time the efficient asymmetric a-alkylation of sulfonamides [90]. After testing some amine auxiliaries mainly based on proline, which did not show high diastereoselectivities, we synthesized the 4-biphenyl-substituted 2,2-dimethyl-l,3-dioxan-5-amine 108 as a new auxiliary. The racemate obtained according to Erlenmeyer s phenylserine synthesis was resolved with tartaric acid to give both enantiomers. 

In a similar study [6], SbCls was complexed with tartaric acid. Also, NaOH was used instead of ammonia, and the solutions were more concentrated... 

Fig. I. Enantioface-differentialing (asymmetric) hydrogenation of MAA to MHB. TA-MRNi RNi catalyst modified with tartaric acid.

Since RNi contains a large amount of aluminum and 2-hydroxy acid is a strong chelating reagent, one difference between RNi and RNiA could be ascribed to their difference in aluminum contents. Table XII (49) shows the correlation between the aluminum content and the EDA of those catalysts modified with tartaric acid. The aluminum content of RNi was decreased by pretreatment with hydroxy acid. Moreover, reduced nickel prepared from NiO (HNi-1) gives an effective modified catalyst and its pretreatment with hydroxyacid does not affect its EDA. 

Enantio-Differentiating Abilities of Various Catalysts Modified with Tartaric Acid"... 

The resolution of the salts was accomplished by means of sodium d-eamphor nitronate or by the action of chloride with tartaric acid. In each case the 1-salt separated first, leaving the d-salt in solution in the mother-liquor. 

The reaction is symbolized 2C102+H20=HC102+HC10S, so that the aq. soln. of N. A. E. Millon s chlorine trioxide will contain a mixture of chloric and chlorous acids and chlorine, and a soln. of the same gas in alkali lye will contain a mixture of the alkali hypochlorite, chlorite, chlorate, chloride. The chlorites are accordingly formed when soln. of chloric acid, HC103, or chlorine dioxide, C102, are partially reduced by the methods employed for the preparation of chlorine di- and tri-oxides. J. E. de Vrij 3 prepared the acid by reducing chloric acid with tartaric acid. G. Bruni and G. Levi used oxalic acid ... 

Lithium.—Lithium oxide was discovered by A. Arfvedson, in 1817,10 while analyzing the mineral petalite. His report was entitled Untersuehungen einiger hei der Eisen-Grube von Ulo vorkommenden Fossilien und von einem darin gefundenen neuen feuerfesten Alkali. He found the sodium to be contaminated by an alkali which, unlike potassium, was not removed as a precipitate by treatment with tartaric acid, and, unlike sodium, it formed a sparingly soluble carbonate. The... 

The first described synthesis of the enantiomeric cetirizine employed resolution of a ( )-chlorobenzhydrylainine as the salt with tartaric acid. Later, an asymmetric synthesis was reported by the Corey group in 1996 (Scheme 7). The pivotal step involved a chiral oxazaborolidine (CBS)-catalyzed reduction of an unsymmetrical chlorobenzophenone with a Tt-chromium tricarbonyl group serving as an effective... 

There are, however, certain chemical reactions by which platinum may be readily distinguished and separated from the gold in solution. Sulphate of iron and oxalic acid, which precipitate gold, do not precipitate platinum. When the latter is dissolved in aqua regia, and the acid neutralized by carbonate of soda, it is deposited as a black powder, if the mixture be boiled with tartaric acid and sodar—the ingredients of a Seid-litz powder. Further, the addition of chloride of ammonium and alcohol te a strong solution of platinum, causes the deposition of a yellow crystalline precipitate, which is charactsristtc of this metal. These and other reactions may be summarily stated as follows... 

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