Tosylate salt

Ph2CHO)3PO, CF3COOH, CH2CI2, reflux, 1-5 h, 70-87% yield. Free alcohols are converted to the corresponding Dpm ethers. This reaction has also been used for the selective protection of amino acids as their tosylate salts (CCI4, 15 min-3 h, 63-91% yield). ... 

Acetylpiperazine [13889-98-0] M 128.2, m 32-34", 52", pK 7.94. Purified by recrystn from 40% aqueous EtOH or from Et0H-Et20. It is an irritant, and is hygroscopic. The hydrochloride has m 191° (from EtOH), and the tosylate has m 148-149° (from EtOH-EtOAc, 1 16). The free base, however, cannot be isolated by basifying the tosylate salt and extractn with CH2CI2. [Chem Ber 66 113 I933 J Am Chem Soc 75 4949 1953, 2570 78 7956.]... 

The primary amine of an amino acid as its tosylate salt can be protected by coordination with a crown ether. The protection scheme was sufficient to allow the HOBt/DDC coupling of amino acids. The crown is removed by treatment with diisopropylethylamine or KCl solution. 

Aerial oxidation of Ru(H20)g+ produces lemon-yellow Ru(H20) + (Ru-O 2.029 A in the tosylate salt)... 

The ruthenium(II) aqua ion reacts with nitrogen at room temperature under high pressure (200 bar) forming yellow-brown [Ru(H20)5N2]2+, isolated as a tosylate salt, showing i/(N=N) at 2141cm-1 in its IR spectrum [59]. 

We report here studies on a polymer fi1m which is formed by the thermal polymerization of a monomeric complex tris(5,5 -bis[(3-acrylvl-l-propoxy)carbonyll-2,2 -bipyridine)ruthenium(11) as its tosylate salt,I (4). Polymer films formed from I (poly-I) are insoluble in all solvents tested and possess extremely good chemical and electrochemical stability. Depending on the formal oxidation state of the ruthenium sites in poly-I the material can either act as a redox conductor or as an electronic (ohmic) conductor having a specific conductivity which is semiconductorlike in magnitude. 

A surface-modified polymeric system can be obtained by spin coating or heating [Ru(L6)3]21 as its / -tosylate salt.16 The resulting film shows seven-color electrochromism whose colors cover the spectral range, which can be scanned in 250 ms. 

With regard to the pressure effects, we have, as usual, been interested in systems that are not simple. One system we have been looking at involves water-soluble porphyrins. Actually, the only reactions we have studied thus far involve the iron(III) and manganese(III) tetra(4-N-methylpyridyl)porphyrin complexes. These complexes are in the form of tosylate salts, which causes some problems. The rate constants are on the order... 

In the BASF BASIL process that utilizes A-methylimidazole to scavenge HCl byproduct, the acidic ionic liquid A-methylimidazolium chloride [HMIMJCl was formed, with a melting point of 75°C (13,102). Recently, the group of Bronsted acidic ionic liquids with the same cation was extended to include other anions, such as BFF, TfO , and TsO . The melting point of the salt is between 30 and 109°C. Strong hydrogen bonding in the tosylate salt was characterized by IR spectroscopy. 

Direct isolation ( one-pot ) processes should be considered for materials prepared for Phase 2 and later development. Examples of this were shown in Schemes 2.3 and 2.4 for the tosylate salt 13 and the product 15 from the Dimroth rearrangement. Considerable processing time may be saved, resulting in lower COG from reduced labor costs. The attendant savings on solvent costs and waste disposal can also reduce COG. Some research time may be necessary to develop these processes, in particular fine-tuning the processes to purge impurities. In early phases of dmg development the fastest scale-up may be through conventional extractive work-up, concentration, and crystallization. 

There are numerous studies of control of racemization for specific subsets of amino acids. For example, Benoiton has carried out extensive studies on racemization of Al-methyl amino acids. In particular, McDermott and Benoiton1261 demonstrated that the presence of tertiary amine salts in coupling reactions had a profound effect on activated TV-methyl amino acids in contrast to the nonmethylated form. In one example, when Z-Ala-MeLeu-OH was coupled to the tosylate salt of Gly-OBzl with ethyl 2-ethoxy-l,2-dihydroquinoline-l-carboxylate (EEDQ) in the presence of TEA, 15% of the l-d dipeptide was formed with a yield of 68%, compared to 0.5% for Z-Ala-Leu-OH with a yield of 78%. When the free base of Gly-OBzl was utilized in a DCC/HOSu coupling in the absence of tertiary amine, no l-d products were detected. The authors attributed this increased susceptibility to epimerization to an ox-azolonium intermediate, which can epimerize by proton abstraction or merely by tauto-merization (Scheme 11). 

Aminofuro[3,2- ]pyridinium tosylates can be prepared from furopyridines by treatment with 0-(4-methylbenzene-sulfonyl)hydroxylamine. Treatment of the tosylate salt with base, such as potassium carbonate, leads to a pyridinium A -imide, 50. Compound 50 readily undergoes 1,3-dipolar cycloaddition reactions <1999CCC539>. 

Horner-Emmons reaction of N-terminal blocked aldehyde 1 with sulfonylphosphonates in the presence of sodium hydride gives the amino acid vinyl sulfone 2, which is deprotected with acid and converted into its chloride or tosylate salt 3 and coupled by the mixed anhydride method with an N-terminal protected peptide or amino acid to give the desired peptide vinyl sulfones 4 (Scheme 2). 4 5 N-Terminal protected aldehydes 1 are obtained from reduction of Boc amino acid V-methoxy-A-methylamides (Weinreb amides, see Section 15.1.1) by lithium aluminum hydride. 9 The V-methoxy-V-methylamide derivatives are prepared by reaction of Boc amino acids with N,O-dimethylhydroxylamine hydrochloride in... 

Guanidinocaproic acid p-tosyl salt and thionyl chloride were mixed together to react at the room temperature. An endothermic reaction occurred and the caproic acid gradually dissolved. Then the reaction mixture was left standing for 1 to 2 h and was extracted with ether. The lower oily layer and the ether layer were separated from each other and the lower layer was repeatedly washed with ether. Then the oily substance (caproic acid chloride) was added with benzoic acid ethyl ester in tetrahydrofuran, and the mixture was stirred. After the mixture became a uniform solution, of pyridine were gradually added. An exothermic reaction occurred and an oily substance came to be separated in the lower layer. After the completion of the reaction, the oily substance was washed with water and then recrystallized from hot water once or twice. Thus 4-(6-guanidino-hexanoyloxy)-benzoic acid ethyl ester salt was obtained as white crystals. 

Conversion to benzazepine was achieved under acidic conditions via hydrogenation in alcoholic solvents to form 25, which did not require isolation. Intermediate 25 was directly cyclized under basic conditions to give crystalline lactam 26. The base-mediated ring closure proceeded from the cis/trans mixture of 25 by epimerization of the benzylic methine permitting formation of the cyclic amide from the cis isomer. Finally, conversion of 26 to the desired benzazepine (8) was accomplished by in situ borane reduction and 8 was isolated as the tosylate salt in 81% yield. 

Preparative Methods (1) is easily made by cy clization of commercially available A-Cbz-r-serine (4) under modified Mit-sunobu conditions, using a preformed complex of dimethyl azodicarboxylate (DMAD) and Triphenylphosphine (eq 1). The reaction proceeds via hydroxy group activation, and labeling studies show that the 3-hydroxy group is lost in a 4-exo-tet cyclization mechanism. The p-lactone must be separated quickly from the reaction mixture, and a slight excess of DMAD improves the yield because unreacted triphenylphosphine can cause polymerization. The Boc (f-butoxycarbonyl) analog (2) is prepared similarly, and the p-toluenesulfonate (tosylate) salt (3) is synthesized from (2) by acidic cleavage. ... 

Method C Via partial saponification of the diesterTo a suspension of powdered TosOH (100 g, 0.525 mol) and H-Glu-OH (75 g, 0.5 mol) in benzyl alcohol (500 mL), benzene (2L) was added and the suspension placed in a three-necked flask. H2O was removed azeotropically. After refluxing for 4d the mixture was cooled, the crystalline product H-Glu(OBzl)-OBzl-TosOH was collected and washed with Et20 to give the tosylate salt yield 196 g (78.5%) mp 144-145 °C,[ I 123-125°C 0 [ ]d +7-3 (c 1, MeOH). 

The use of other acylating agents is illustrated by the following. 4-Amino-l-methyl-5-oxamoylaminomethyltriazole (24) (as tosylate salt), when refluxed in an excess of trifluoroacetic acid, produced l-methyl-5-oxamoylamino-methyl-4-trifluoroacetamidotriazole (1 day, 83%) [81J(P1)887]. 4-Amino-... 

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