Maleate, solution preparation

Prepare a solution of tris acid maleate 50 mM by mixing 6 g of tris(hydroxymethyl)aminomethane and 5.8 g of maleic acid in 1 L H O. Prepare a 50 ruM NaOH solution. Mix the 50 mL of the tris acid maleate solution and 48 mL of NaOH solution. Verify and adjust the pH by adding one of the Tris acid maleate or NaOH solutions. 

Preparation of silver maleate. Dissolve 65 g. of pure maleic acid (Section 111,143) in the calculated quantity of carefully standardised 3-5N aqueous ammonia solution in a 1-htre beaker and add, whilst stirring mechanically, a solution of 204 g. of silver nitrate in 200 ml. of water. Filter oflf the precipitated silver maleate at the pump, wash it with distilled water, and press well with the back of a large flat glass stopper. Dry in an electric oven at 50-60° to constant weight. The yield of the dry silver salt is 150 g. Store in a vacuum desiccator in the dark. 

A solution of N-(2-aminobenzvl)-1-phenyl-2-metKylaminoethanol-1 was prepared by the reaction of a-bromo-acetophenone and (2-nitrobenzyl)methylamine, followed by hydrogenation of the nitro group by means of nickei on diatomaceous earth at room temperature and reduction of the CO group by means of sodium borohydride. The intermediate thus produced was dissolved in 100 ml of methylene chloride and introduced dropwise into 125 ml of sulfuric acid at 10° to 15°C. After a short standing, the reaction mixture was poured onto ice and rendered alkaline by means of a sodium hydroxide solution. Dy extraction with ether, there was obtained 1,2,3,4-tetrahydro-2-methyl-4-phenyl-8-amino-iso-quinoline. The base is reacted with maleic acid to give the maleate melting point of the maleate 199° to 201°C (from ethanol). 

Alternative Step D Reduction with a Reductate — Sucrose (1 kg) is dissolved in water (9 liters) in a 20-liter bottle equipped with a gas trap. Baker s yeast Saccharomyces cerevisiae, 1 kg) is made into a paste with water (1 liter) and added to the sucrose solution with stirring. After lively evolution of gas begins (within 1 to 3 hours), 3-morpholino-4-(3-tert-butylamino-2-oxopropoxy)-1,2,5-thiadiazole hydrogen maleate [1.35 mols, prepared by reaction of the 3-morpholino-4-(3-tert-butylamino-2-oxopropoxy)-1,2,5-thiadiazole with an equimolar quantity of maleic acid in tetrahydrofuran]. The mixture is allowed to stand until fermentation subsides, after which the bottle is kept in a 32°C incubator until all fermentation has ended (in approximately 1 to 3 days). The yeast is filtered off with addition of diatomaceous earth and the filtrate is evaporated to dryness to give S-3-mor-pholino-4/3-tert-butylamino-2-hydroxypropoxy)-1,2,5-thiadiazole, MP 195° to 198°C (as hydrogen maleate), according to U.S. Patent 3,619,370. 

Ethyl fumarate has been prepared from fumaric acid and ethyl alcohol, with or without sulfuric acid as catalyst,4 from silver fumarate and ethyl iodide,5 from silver maleate and ethyl iodide plus a trace of iodine,6 from ethyl maleate by the action of iodine,6 from ethyl maleate and phosphorus pentachloride,7 and by passing hydrogen chloride into a boiling absolute alcohol solution of malic acid.8... 

Materials Required Solution (1) dilute 1 volume of solution (3) to 200 volumes with a 0.005% w/v solution of N-phenylcarbazole (internal standard) in toluence 10 ml Solution (2) (add 5 ml of DW to 0.1 g of bromopheneramine maleate sample, make the resulting solution alkaline with 13.5 M ammonia, add 2.5 ml of toluene, shake for 5 minutes, centrifuge and use the upper layer) solution (3) (prepare it exactly in the same manner as solution- 2 but using the internal standard solution in place of toluene) Solution (4) (dissolve 10 mg of bromopheneramine maleate BPCRS in 5 ml of DW, make alkaline with 13.5 M ammonia, add 2.5 ml of toluene, shake for 5 minutes, centrifuge and dilute 1 volume of the upper layer to 20 volumes with toluene) ... 

Pharmaceutical grade ibuprofen, pseudoephedrine HCl, chlorpheniramine maleate, nipagen and syrup preparation were kindly supplied by Berko tlag Sanayi A. , Istanbul. 0.03 M H PO and KH PO solutions were prepared with analytical grade chemicals and milliQ water. HPLC grade acetoiutrile was used. 

The ion Cu" is extremely labile. Rate constants for the formation of maleate or fumarate complexes are =10 M s Ref. 281. It can be prepared in an acid perchlorate solution by reaction of Cu with a one-electron reducing agent such as Cr, or Eu Ref. 282. Although there is a marked tendency for disproportionation, solutions of Cu are metastable for hours in the absence of oxygen, particularly when concentrations of Cu(I) are low and the acidity is high. Espenson has capitalized on this to study the rates of reduction by Cu of some oxidants, particularly those of Co(III), Table 5.7 (see Prob. 6(c) Chap. 5). 

Method A. A slurry of 3.15 g d-lysergic acid monohydrate (monohydrate means dry) and 7.3 g of diethylamine (or 0.1 mole of similar amine) in 150 ml of pure chloroform is heated to reflux. After the lysergic acid is dissolved (a few min) cool the mixture down to where reflux has stopped by removing the heat. Before the mixture cools any further 2 ml of phosphorous oxychloride is added at such a rate as to give reflux (about 2 min). After addition, reflux for 4-5 min further until an amber-colored solution results. Cool to room temp and wash the mixture with 200 ml of 1 M ammonium hydroxide. The chloroform solution was dried with MgSC>4 (this would have to be after separation), filtered, and concentrated by evaporation in vacuo under a temp of 38° (at no time let the temp go over 40°). The last traces of solvent are removed at 2-5 mm. Dissolve the residue in a minimum amount of methanol and acidify with freshly prepared solution of 20% maleic acid in methanol (not aqueous) to precipitate the LSD in its maleate form. Filter the fluffy white needles, wash with cold methanol and air dry to get 2.2 g of LSD that requires no further purification. 

Method B. cWV-rerf-ButyUysergamide Maleate (lb). A refluxing slurry of 3.15 g of d-lysergic acid in 150 ml of CHCls was treated with 7.1 g (96 mmol) of ferf-butylamine in 25 ml of CHCls and 2 ml of POCh which were added simultaneously from separate dropping funnels over 2-3 min. The reaction mixture was kept at reflux for another 3-5 min until a clear, amber solution resulted. The solution was cooled to room temperature and worked up in the same manner as described above giving 2 g of lb. The reactants were scaled up eight times for the preparation of le. 

Such perfect cases of equilibration are rare. Another important one concerns equilibration by Michael addition to conjugated alkenes. A classic case is the preparation of maleate 47 and fumarate 48 esters from (the necessarily Z-) maleic anhydride 46. Simple treatment with methanol in acidic solution gives the liquid maleate 47 as expected. It is unusual for cis and trans alkenes to be given different names maleic and fumaric acids were named before their relationship was understood. 

Cough-cold preparations Paracetamol, dextromethorphan hydrobromide and chlorpheniramine maleate in antitussive syrups Partition Permaphase ODS Methanol/buffer solution... 

Hydrocarboxylation of acetylene. Italian chemists have prepared a very active catalyst for hydrocarboxylation reactions from palladium(II) chloride and 2 eq. of thiourea. When acetylene, carbon monoxide, and oxygen are passed into a solution of the catalyst in methanol at room temperature, dimethyl maleate is... 

PA toughened by incorporation of solution-maleated SEES CORI Blends can also be prepared in solution or using internal mixer GeUes et al., 1994... 

A maleated ester of low density polyethylene, prepared by the reaction of LDPE and dibutyl maleate in solution, was blended with TPS by reactive extrusion. Mechanical properties of the blends were similar to those of the LDPE due to the compatibilization of these dissimilar components [75]. 

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