Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Addition salts

In addition, salts deactivate reforming and catalytic cracking catalysts. [Pg.329]

The trihydrate which is obtained in high yields, is relatively insoluble in water, possesses high biological stability and can be obtained by contacting, at a temperature not above 60°C, an acid addition salt of D-(-)-a-aminobenzylpenicillin with an amine in a water-immiscible solvent containing at least 3 mols of water per mol of such penicillin. [Pg.90]

The filtrate containing the capreomycin is added to 240 liters of methanol with stirring. The methanolic solution of capreomycin is acidified by the addition of one liter of ION sulfuric acid, whereupon the precipitation of the sulfuric acid addition salt of capreomycin commences. The mixture is permitted to stand overnight for more complete precipitation. The supernatant is removed by decanting and filtering. The precipitate, consisting of the capreomycin disulfate, is washed with 10 liters of methanol and is dried in vacuo. Yield 2,510 grams. [Pg.226]

The hydrochloride addition salt of the above reaction product was prepared in customary fashion, that is, by reaction with hydrochloric acid, followed by fractional crystallization from a mixture of alcohol and ether. The two possible racemic forms were obtained thereby. The difficultly soluble racemate had a melting point of 169° to 170°C and the more readily soluble racemate had a boiling point of 145° to 148°C. [Pg.362]

To a solution of 5 g of sisomicin in 250 ml of water add 1 N sulfuric acid until the pH of the solution is adjusted to about 5. To the solution of sisomicin sulfuric acid addition salt thereby formed, add 2 ml of acetaldehyde, stir for 10 minutes, then add 0.B5 g of sodium cyanoborohydride. Continue stirring at room temperature for 15 minutes, then concentrate solution In vacuo to a volume of about 100 ml, treat the solution with a basic ion exchange resin [e.g., Amberlite IRA401S (OH )], then lyophilize to a residue comprising 1-N-ethyl-sisomicin. [Pg.1066]

A solution of 200 g of 1 -p-chlorophenvl-2-phenyl-4-(N-pvrrolidino)-butanol-2 in 750 ml of concentrated hydrochloric acid is refluxed for 9 hours thereby causing a dehydration of the butanol compound, and the formation of the hydrochloric acid addition salt of a 1 -p-chloro-phenyl-2-phenyl-4-(N-pyrrolidino)-butene. The hydrochloride salt formed crystallizes in the oily lower layer of the two phase reaction mixture and is removed therefrom by filtration. The filtrate is again refluxed for 9 hours, cooled to0°C,and a second crop of the hydrochloric acid addition salt of the dehydration product is obtained and filtered off. The filtrate containing residual amounts of 1 -p-chlorophenyl-2-phenyl-4-(N-pyrrolidino)-butanol-2 is again refluxed for 9 hours to yield an additional crop of the salt of the dehydration product. The several fractions of the butene compound are combined and triturated with several small portions of hot acetone and recrystallized from alcohol-ether mixture. The hydrochl or ic acid addition salt of the dehydration product, 1 -p-chlorophenyl-2-phenyl-4-(N-pyrrolidino)-butene hydrochloride, melts at about 227°C to 228°C. [Pg.1340]

Treatment of the above hydrobromide with aqueous sodium bicarbonate followed by extraction with ethyl acetate yields the free base of the carbinol MP 203° to 204°C which may be reacted with other acids to give other acid addition salts. [Pg.1360]

Additional salt is precipitated by the addition of ether to the ethanolic filtrate, but the quantity is so small that this treatment is not worth while. [Pg.103]

Many substances that participate in aqueous reactions are soluble salts. These ionic solids dissolve in water to give solutions of cations and anions. For almost all salts, there is an upper limit to the amount that will dissolve in water. A salt solution is saturated when the amount dissolved has reached this upper limit of solubility. Any additional salt added to a saturated solution remains undissolved at the bottom of the vessel. When excess solid... [Pg.1186]

During improved oil-recovery processes, waterflooding of the oil is applied. The entrained water forms a water-in-oil emulsion with the oil. In addition, salts such as sodium chloride, calcium chloride, and magnesium chloride may be dissolved in the emulsified water. [Pg.326]

The classic syntheses of the antibacterial sulfonamides involve reaction of the appropriate arylamine with an acid addition salt of p-amino-benzenesulfonyl chloride, or p-nitrobenzenesulfonyl chloride followed by reduction. Chemical interest largely resides in preparation of the corresponding arylamines. For the synthesis of sulfacytine (134), N-ethyl uracil (131) was converted to its thioamide (132) by reaction with phosphorous pentasulfide. The newly introduced sulfur is then displaced with ammonia in methanol to give 133. Standard reactions complete... [Pg.113]

The prior art Sanofi patent made statements concerning enantiomers and addition salts. [Pg.456]

Apotex wove these facts into a prima facie case of obviousness as follows It would be obvious to separate an enantiomer from a known racemate using generally known techniques. Furthermore, there was motivation [19] to do so because enantiomers can have different properties from those displayed by the racemate, and because of a possible future FDA regulatory requirement for separation of enantiomers. Additionally, there was a reasonable expectation of success [20] in achieving the separation because techniques for separating enantiomers from racemates are known. And finally, it would be obvious to form an addition salt of the enantiomer to optimize selected physical properties. Thus, concluded Apotex, dextrorotatory clopidogrel bisulfate was obvious, it is therefore unpatentable, and this renders the 265 patent invalid. [Pg.456]

Another aspect that may be taken into account is that of membrane electrolysers having a lower power consumption (Fig. 15.4). Not only does the new technology save power but it also requires less steam to evaporate the cell caustic product to 50%. Additionally, salt removal equipment required in diaphragm plants uses power. This benefit can also be turned around so that for the same power consumed by a diaphragm cell room extra volumes of rayon-grade caustic soda can be produced from the membrane electrolysers. [Pg.199]

A combination of crystallographic and NMR methods was used to obtain the high-resolution structure of the domain of a Hsp from the thermophilic T. thermophilus (Tm > 100 °C) and to compare it to the homologous domain of Hsp from E. coli T = 65 °C). It was found that the structure of the domain of the T. thermophilus Hsp contained additional salt bridges which could be responsible for the higher thermostability. ... [Pg.138]

If salt is present in the solution, counterions as well as co-ions do penetrate into the brush, which leads to additional screening of the Coulomb repulsion inside the brush. The amount of this screening, and the stretching of the polyelectrolyte chains, are now also controlled by the bulk salt concentration. Since the additional salt screening weakens the swelling of the brush caused by the counterion osmotic pressure, salt leads to a brush con-... [Pg.179]

Glycerine can also be purified by the use of ion-exchange resins to remove sodium chloride salt, followed by evaporation of the water. This process puts additional salts into the wastewater but results in less organic contamination. [Pg.319]

The vibrational spectra of pertechnetates have only lately been widely studied. Busey and Keller (86) have reported the original IR and Raman spectra of crystalline KTCO4. The measurements were later completed (85, 115). Additional salts have also been measured (107). All these data are collected in Table 13. The IR data for tetraphenylarsonium and tetraphenylphosphonium pertechnetate can be found in Ref. (115). The vi(A ) stretch in pertechnetates has been observed in the Raman effect and found to lie at 910 cm i for KTCO4 (84). [Pg.90]

In addition to the cations diseussed above, additional salts of the monoanion 2a have been prepared by substituting various pyridinium salts for the BU4NI utilized in Seheme 2. A signifieant number of salts of 2a have also been prepared via metathesis of [Bu4N][2a] with various metal PFe salts. These methods have thus produced salts of 2a with various organometallic cations ([M(Cp )2], were M = Fe, Mn, Co, Cr). [Pg.72]

Certain additives, salts, and bulking agents may be added primarily to improve vaccine stability upon storage (19,20). These excipients such as mannitol, glycine, and trehalose have a direct impact on the stability of the polypeptide or conjugate and are investigated for this purpose. [Pg.337]


See other pages where Addition salts is mentioned: [Pg.233]    [Pg.153]    [Pg.93]    [Pg.109]    [Pg.412]    [Pg.972]    [Pg.1340]    [Pg.1473]    [Pg.29]    [Pg.45]    [Pg.106]    [Pg.459]    [Pg.459]    [Pg.460]    [Pg.213]    [Pg.199]    [Pg.320]    [Pg.2]    [Pg.458]    [Pg.132]    [Pg.53]    [Pg.55]    [Pg.45]    [Pg.414]    [Pg.19]    [Pg.130]    [Pg.799]    [Pg.290]    [Pg.137]    [Pg.174]   
See also in sourсe #XX -- [ Pg.154 ]




SEARCH



Addition of various salts

Addition reactions salt effects

Addition to imines, iminium salts and related compounds

Additional 1-1 Type Organic Salts

Additions to Unsaturated Phosphonium Salts

Additions to Vinylphosphonium Salts

Additives sulfate salts

Aldol addition ammonium salt

Alkyne Addition to the Transition Metal Salts and Complexes

Arenediazonium salts radical addition reactions

Aryldiazonium salts addition reactions

Carbon dioxide, addition salts

Copper salts as additives

Copper salts effect on conjugate addition of Grignard

Cuprate, bis lithium salt conjugate addition to a,(3-unsaturated esters

Cuprate, dialkyllithium salt conjugate addition to enones

Diazonium salts electrophilic addition

Environmental salt addition effect

Fillers, salts, and other additives for composites preparation

Imidazolium salts, nucleophilic addition

Iminium salts nucleophilic addition

Iminium salts, addition

Iminium salts, addition Diels-Alder reaction

Iminium salts, addition amines with aldehydes

Iminium salts, addition cyanide

Iminium salts, addition from aldehydes

Iminium salts, addition hydrolysis

Iminium salts, addition ketones

Iminium salts, addition reaction

Iminium salts, addition rearrangement

Iminium salts, addition with Grignard reagents

Isoquinolinium salts nucleophilic addition

Isoquinolinium salts, Grignard addition

Isothiocyanates, addition salts

Lewis Acid Promoted Additions of Organotrifluoroborate Salts

Mercuric salts in addition reactions of alkenes

Mercuric salts in addition reactions of alkynes

Metal salts, addition

Metal salts, addition acylals

Metal salts, addition carbonyls

Metal salts, addition radical cyclization

NH4PF6 salt additive

Nitriles, acid catalyzed addition salts

Nucleophilic addition reactions lithium salts

Nucleophilic addition salt effects

Nucleophilic addition to pyridinium salts

Olefin Addition to the Transition Metal Salts

Organolithium reagents, addition salts

Palladium salts alkene addition reactions

Phase-Transfer-Catalyzed Addition of Anion Supplied as Metal Salt

Phosphonium salts addition reaction of phosphine

Polymer/salt complexes polar molecule addition

Pyrazinium salts addition

Pyridinium salts Grignard addition

Pyridinium salts addition reactions

Pyridinium salts enolate addition

Pyridinium salts nucleophilic addition

Salt addition method

Salt additives

Salt additives, deliquescent, effect

Zinc salt, additive action

Zinc salt, additive mechanism

© 2024 chempedia.info