Anisole crystallization solvent

Then, 1-(3-acetylthio-2-methylpropanoyl)-L-proline is produced. The 1-(3-acetylthio-3-methyl-propanoyl)-L-proline tert-butyl ester (7.8 g) is dissolved in a mixture of anisole (55 ml) and trifluoroacetic acid (110 ml). After one hour storage at room temperature the solvent Is removed in vacuo and the residue is precipitated several times from ether-hexane. The residue (6.8 g) is dissolved in acetonitrile (40 ml) and dicyclohexylamine (4.5 ml) is added. The crystalline salt is boiled with fresh acetonitrile (100 ml), chilled to room temperature and filtered, yield 3 g, MP 187°C to 188°C. This material is recrystallized from isopropanol [ttlo -67° (C 1.4, EtOH). The crystalline dicyclohexylamine salt is suspended in a mixture of 5% aqueous potassium bisulfate and ethyl acetate. The organic phase is washed with water and concentrated to dryness. The residue is crystallized from ethyl acetate-hexane to yield the 1-(3-acetylthio-2-D-methylpropanoyl-L-proline, MP83°Cto 85°C. 

In a 500 ml round-bottomed flask equipped with a magnetic stirrer are placed 22 5 g (0 105 mole) of powdered sodium metaperiodate and 210 ml of water The mixture is stirred and cooled m an ice bath (Note 1), and 12 4 g (0 100 mole) of thio-anisole (Note 2) is added The reaction mixture is stirred for 15 hours at ice-bath temperature and is then filtered through a Buchner funnel The filter cake of sodium iodate is washed with three 30-ml portions of methylene chloride The wrater methylene chloride filtrate is transferred to a separatory funnel, the lower methylene chloride layer is removed, and the water layer is extracted with three 100-ml portions of methylene chloride The combined methylene chloride extracts are treated with activated carbon (Note 3) and dried over anhydrous sodium sulfate (Note 4) The solvent is removed at reduced pressure to yield 13 6-13 9 g of a slightly yellow oil (Note 5) which crystallizes on cooling The crude sulfoxide is transferred to a 25 ml distillation flask with the aid of a small amount of methylene chloride After removal of the solvent, a pinch of activated carbon is added to the distillation flask (Note 6) Simple vacuum distillation (Note 7) of the crude product through a short path still affords 12.7-12 8 g (91%) of pure methyl phenyl sulfoxide, b p 78-79° (0 1 mm ), m p. 33-34° (Notes 8 and 9)... 

When the magnesium alkyl compound does not form readily, i. e. in using aryl halides, a crystal of iodine is often added to start the reaction. Other solvents than ether have been used, i. e. anisole, phenyl amyl ether, and dimethyl-aniline. The solvent apparently combines with the compound MgRX forming intermediate products R20.MgRX and R3N.MgRX, and acts as a catalyst, since it has been found that the reactions proceed in benzene or xylene provided a small amount of ether or dimethyl-aniline be added. 

A mixture of Yb(OTf)3 (620 mg, 1 mmol), anisole (1, 540 pL, 5 mmol), and acetic anhydride (940 pL, 10 mmol) in nitromethane (5mL) was stirred at 50 °C for 4h. After dilution with water (10 mL), the mixture was extracted with dichlorometh-ane. The organic layers were combined and dried over NaS04. After filtration and evaporation of the solvents, the crude mixture was purified by column chromatography on silica gel to afford 4-methoxyacetophenone (2). The aqueous layer was concentrated in vacuo to give a crystalline residue, which was heated at 190 °C for 4h in vacuo to afford 576.6 mg (93 %) Yb(OTf)3 as colorless crystals. The recovered Yb(OTf)3 was reused in the next acylation reaction. All products of the acylation of aromatic compounds shown in this chapter are known compounds and are commercially available. 

Novel lanthanide fi-diketonate complexes have been synthesized, Their properties include thermal, hydrolytic and oxidative stabilities, volatility, Lewis acidity, and unusually high solubility in nonpolar organic solvents. Various combinations of these properties make lanthanide complexes useful as NMR shift reagents and fuel antiknock additives and in other applications. NMR spectral studies revealed that the Pr(III), Yb(III), and Eu(III) complexes of 1,1,1,2,2,3,3,7,7,7- decafluoro-4,6-heptanedione have sufficient Lewis acidity to induce appreciable shifts in the proton resonances of weak Lewis bases such as anisole, acetonitrile, nitromethane, and p-nitrotoluene. Data from single-crystal structure determinations indicate that the NMR shift reagent-substrate complexes are not stereochemically rigid and that effective axial symmetry may exist by virtue of rapid intramolecular rearrangements. 

To a stirred solution of 7.6 g of 3-ethoxy-2-(methylthio)anisole in 100 mL CH2CI2 there was added 6.2 g elemental bromine dissolved in 50 mL CH2CI2. The initial dark red color gradually faded to a pale yellow and there was a steady evolution of HBr. An added crystal of iodine did not appear to increase the rate of reaction. After 4 min the color was a pale orange. The reaction mixture was extracted with H20 containing sufficient dithionite to remove most of the residual color. The solvent was removed under vacuum leaving 12.2 g of a pale yellow fluid oil. This was distilled at 100-110 deg C at 0.3 mm/Hg to yield a mixture of 4-bromo-3-ethoxy-2-(methylthio)anisole and 6-bromo-3-ethoxy-2-(methylthio)anisole as a pale yellow, highly... 

To a round-bottom flask equipped with a magnetic stirring bar, were added tetrazole 39 (352 mg, 2 mmol), anisole (20 mL) and fumaryl chloride (153 mg, 1 mmol). While stirring, collidine (242 mg, 2 mmol) diluted with anisole (2 mL) was added dropwise and the flask was connected to a gas burette. The flask was heated at 85 °C until gas evolution occurred and kept at this temperature. As the gas evolution ceased, the bath temperature was raised about 20 °C and kept for further 20 min. The mixture was cooled and poured on a chromatography column filled with silica gel and petroleum ether/toluene 1 1. After the solvent was eluted, toluene with gradually increased content of EtOAc was used as an eluent to give the titled compound (318 mg, 92%) as colorless crystals. 

Many of the calixarenes retain the solvent from which they are crystallized. Crystal structures by Andreetti et al (126) of (128)-toluene complex show the calix to be in the cone conformation and the toluene located in the centre of the calix, i.e. an endo -calix complex (Figure 2.55). A recent publication by the same group (129) shows two molecules of (128) in the cone conformation encapsulating one molecule of anisole. 

Poly(ethylene terephthalate) is most usually encountered in the crystalline form and, as such, it is soluble at normal temperatures only in proton donors which are capable of interaction with the ester group. Effective solvents of this kind are chlorinated and fluorinated acetic acids, phenols and anhydrous hydrofluoric acid. The polymer is soluble at elevated temperatures in various organic liquids, which include anisole, aromatic ketones, dibutyl phthalate and dimethyl sulphone. Chloroform has the peculiar property of dissolving amorphous poly(ethylene terephthalate) at temperatures below 0°C,but on warming such solutions the polymer separates in crystalline form. Chloroform is without effect on polymer which has already been crystallized. 

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