Of isopropyl ether

A solution of 1.7 g of 2-hydroxymethyl-3-benzyloxy-(1-hydroxy-2-tert-butyl-aminoethyl)py-ridine in 30 ml of methanol containing 1.2 ml of water is shaken with 700 mg of 5% palladium-onatmospheric pressure. In 17 minutes the theoretical amount of hydrogen has been consumed and the catalyst is filtered. Concentration of the filtrate under reduced pressure provides 1.4 g of the crude product as an oil. Ethanol (5 ml) Is added to the residual oil followed by 6 ml of 1.75N ethanolic hydrogen chloride solution and, finally, by 5 ml of Isopropyl ether. The precipitated product is filtered and washed with isopropyl ether containing 20% ethanol, 1.35 g, melting point 182 (dec.). 

This reaction mixture is kept between 0°C and -i-5°C for six hours, with agitation and under an inert atmosphere, then 5 cc of a 0.2N solution of acetic acid in toluene are added. The mixture is extracted with toluene, and the extracts are washed with water and evaporated to dryness. The residue is taken up in ethyl acetate, and then the solution Is evaporated to dryness in vacuo, yielding a resin which is dissolved in methylene chloride, and the solution passed through a column of 40 g of magnesium silicate. Elution is carried out first with methylene chloride, then with methylene chloride containing 0.5% of acetone, and 0.361 g Is thus recovered of a crude product, which is dissolved in 1.5 cc of isopropyl ether then hot methanol Is added and the mixture left at 0°C for one night. 

Samples for studies of CDx effects on fluorescence enhancement in organic solution were prepared using pyrene, because pyrene possesses a long lifetime and is very susceptible to quenching and enhancement in solution (23). An aliquot of pyrene stock solution in cyclohexane was placed under a nitrogen purge to evaporate the cyclohexane. Samples were redissolved in a 1 A mixture of Isopropyl ether and 1-butanol, which was saturated with aqueous CDx solution. Pyrene samples were also prepared in which the organic solvent was not saturated with CDx solution. The mixed solvent was used in order to minimize the effects of ether evaporation and thus allow more accurate quantitation. Fluorescence measurements were made on diluted samples of these solutions. The solvent used to make up the... 

The observed formation of isobutyrate (Figs. 5 and 6) would appear to be one of the possible reasons for the slow decrease in the nitroxide concentration. The formation of isobutyrate can be seen as a reaction competing with the capture of the acyl radicals by oxygen. The absence of isopropyl ether in the reaction mixture is explained by its immediate cleavage - following its formation analogous to isobutyrate - to nitroxide by oxygen-centered radicals (mainly acyl peroxy radicals). 

Illustrate the layered accident investigation process, using Example 13-1 as a guide, to develop the underlying causes of the duct system explosion described in section 13-1. 13-2. Repeat Problem 13-1 for the bottle of isopropyl ether accident described in section 13-2. 13-3. Repeat Problem 13-1 for the nitrobenzene sulfonic acid decomposition accident described in section 13-2. 

In experiment Rll the reaction mixture was treated with 14C-labelled 2-propanol, and the resulting polymer contained negligible activity. It follows that the reaction of the end-groups with the alcohol does not produce a detectable concentration of isopropyl ether end-groups. When the alcohol was added to the reaction mixture, the conductivity fell to zero within half a minute, which indicated a rapid removal of ions from the organic phase. 

Following the successful demonstration of an enamine photocyclization, Ninomiya synthesized ( )-cryptaustoline iodide from 44b. Irradiation of isopropyl ether 44b gave a mixture of dibenzopyrrocolines 45b and 45c in 12 and 11% yield, respectively. The isopropyl ether group in 45c was selectively hydrolyzed by hydrobromic acid, and the resulting phenolic compound was converted to cryptaustoline iodide with methyl iodide. An attempt to photocyclize an O-benzyl ether analog of 44b was less satisfactory. 

A flask was charged with 1-(1,1-dimethyl-2,2-ditrifluoromethyl-2-hydroxyl)ethyl methacrylate (176.46 g), l-(l-cyclohexyl-2,2-ditrifluoromethyl-2-hydroxyl)ethyl methacrylate (23.54 g), dimethyl 2,2 -azobisisobutyrate (3.74 g), and isopropyl alcohol (100.0 g) and then cooled to 20-25°C. In a separate flask isopropyl alcohol (50.0 g) was heated to 80°C and then added dropwise to the monomer solution over 4 hours and then stirred for 3 hours at 80°C. The solution was then cooled to ambient temperature and then precipitated in 4 liters of water and then isolated. The copolymer was washed four times with 600 g of isopropyl ether/hexane, 9 1, respectively, and a white solid isolated. After vacuum drying 90.1 g of the product was isolated having an Mw of 9600Da with a polydispersity of 1.6 and consisting of 80/20mol% 1-(l,l-dimethyl-2,2-ditrifluoromethyl-2-hydroxyl) ethyl methacrylate and l-(l-cyclo-hexyl-2,2-ditrifluoromethyl-2-hydroxyl)ethyl methacrylate, respectively. 

Penicillin can be purified by extraction. The distribution coefficient for penicillin G between isopropyl ether and an aqueous phosphate medium is 0.34 (lower solubility in ether). The corresponding ratio for penicillin F is 0.68. A preparation of penicillin G has penicillin F as a 10.0% impurity, (a) If an aqueous phosphate solution of this mixture is extracted with an equal volume of isopropyl ether, what will be the % recovery of the initial G in the residual aqueous-phase product after one extraction What will be the % impurity of this product (b) Calculate the same two quantities for the product remaining in the aqueous phase after a second extraction with an equal volume of ether. 

To a round flask which has been well dried and flushed with nitrogen are added 85.0 g (1.1 mol) of sodium amide (50% suspension in toluene) and 180.0 g of isopropyl ether and there are now added dropwise thereto at a temperature of 50°-60°C 150.2 g (1 mol) of acetylanisole in 180.0 g of isopropyl ether. Reaction sets in immediately and a white paste-like mass forms. After completion of the addition, the mixture is stirred for a further 0.5 h and then 192.3 g of p-t-butylbenzoic acid methyl ester are added rapidly at 25°-30°C. The mixture is stirred for 0.5 h at room temperature, then for 3 h at 60°-70°C and left to stand for 12 h. 200.0 g of ice are then added and the mixture is acidified with 128.0 g (1.1 mol) of technical hydrochloric acid and 200 ml of ice-water. The mixture is stirred until the sodium salt of the product has dissolved. The phases are separated and the organic phase is washed with ice-water until neutral. The organic phase is concentrated on a rotary evaporator and there are thus recovered 290.0 g of isopropyl ether. The yield of 4-(l,l-dimethylethyl)-4 -methoxydibenzoylmethane, melting point 83.5°C is 199.8 g (64.5%) (recrystallisation from methanol). 

A suspension of 10.0 g (0.026 mole) of [[2-methyl-l-(l-oxopropoxy)propoxy] (4-phenylbutyl)phosphinyl]acetic acid in 50 ml of isopropyl ether was stirred vigorously for 15 min, then kept at 5°C for 20 hours. The colorless product was filtered, washed with a small amount of cold isopropyl ether to give 5.0 g of [[2-methyl-l-(l-oxopropoxy)propoxy](4-phenylbutyl)phosphinyl]acetic acid (A/B isomer, racemic mixture), m.p. 87-89°C. The filtrate was evaporated in vacuo and retained for isolation of isomer C/D. A solution of the above material in 110 ml of hot isopropyl ether was filtered through a hot glass funnel (glass wool). The cooled solution gave 4.6 g (92%) of desired product, m.p. 90-92°C. 

The following route is described in US Patent 4,145,552 At ambient temperature, over a period of thirty minutes, a solution of 33.8g (O.lmol) of (-)-vincadiformine in a mixture of 140 ml of anhydrous dimethylformamide and 140 ml of anhydrous toluene is added to a suspension of 2.64 g (0.11 mol) of sodium hydride in a mixture of 200 ml of anhydrous tetrahydrofuran, 20 ml of anhydrous hexamethylphosphotriamide (EMPT) and 18.7 ml (0.14 mol) of trimethyl phosphite. When the release of hydrogen has finished (about two hours later), the solution is cooled to -10°C and then stirred under an oxygen atmosphere until absorption ceases (duration 3 hours). Still at -10°C, 136 ml of glacial acetic acid are added, and the mixture is then left at ambient temperature for two hours. After the addition of 500 ml of 1 N sulfuric acid, the aqueous phase is isolated, reextracted with 150 ml of isopropyl ether, made alkaline with 350 ml of 11 N ammonia, then extracted 3 times with 300 ml aliquots of methylene chloride. After drying over calcium... 

C. Place about 5 mg of sample into a test tube, add 5 mL of water, 1 mL of a freshly prepared 1 100 naphtholresorcin-okethanol solution, and 5 mL of hydrochloric acid. Heat the mixture to boiling, boil gently for about 3 min, and then cool to about 15°. Transfer the contents of the test tube to a 30-mL separator with the aid of 5 mL of water, and extract with 15 mL of isopropyl ether. Perform a blank determination (see General Provisions), and make any necessary correction. The isopropyl ether extract from the sample exhibits a deeper purple hue than that from the blank. 

The total volune is about 20 ml. A fresh 30 ml portion of Isopropyl ether is added and shaken with an aqueous soln. for one min, and the acid phase separated ... 

The aqueous phases ere combined and washed with another freBh portion of isopropyl ether. 

Trichloroalane in dichloromethane cleaves isopropyl aryl ethers leaving methyl aryl ethers intact. A variety of functional groups (aryl halides, 1,1-dihaloalkenes, aldehydes and acetates) withstand the reaction conditions but alkynes and TIPS ethers do not survive. Scheme 4 110 illustrates an application of the reaction to a synthesis of the Fagaronine alkaloids,201 TVichloroborane in dichloromethane may also be used for the deprotection of isopropyl ethers.202... 

A more complete extraction " of polysaccharides was attempted by refluxing the soil for two 30-minute periods with 98 % formic acid containing lithium bromide. The organic matter extracted was precipitated by the addition of isopropyl ether and was redispersed in lithium chloride solution. The colored humic substances were then precipitated with hexadecyltri-methylammonium bromide, while the acidic and neutral polysaccharides were kept in solution by the lithium chloride. The possible degradative effects of hot formic acid on soil polysaccharides have not yet been investigated. 

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