Big Chemical Encyclopedia

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

Articles Figures Tables About

Ethers acetic anhydride

P-Cyclopentylpropionic acid Testosterone 3-enol-ethyl ether Acetic anhydride Hydrogen chloride... [Pg.3169]

As many as 70 products were at one time produced commercially from ethanol. Some of these downstream products are butanol, 2-ethyl hexanol, crotonaldehyde, butyraldehyde, acetaldehyde, acetic acid, butadiene, sorbic acid, 2-ethylbutanol, ethyl ether, many esters, ethanol-glycol ethers, acetic anhydride, vinyl acetate, ethyl vinyl ether, even ethylene gas. Many of these products are now more economically made from other feedstocks such as ethylene for acetaldehyde and methanol-carbon monoxide for acetic acid. Time will tell when a revival of biologically-oriented processes will offer lower-cost routes to at least the simpler products. [Pg.58]

Hydroxymethylation of ketone (155) was followed by protection of the aliphatic hydroxy group (2-methoxypropyl ether) and addition of an a-benzyloxymethylene group at C-4. Acidic workup at the last stage of the reaction sequence produced (156). Its transformation to aldehyde (157) was carried out by successive treatment with methoxypropyl ether, acetic anhydride and pyridine, hydrochloric acid and methanol, and finally chromic acid, pyridine and hydrochloric acid. Dehydration of (157) led to the formation of (158) in 20% yield. Reagents other than the mentioned produced appreciable quantities of the cis A/B isomer. The butenolide (159) was finally synthesized by oxidation and hydrogenolysis. In order to complete the synthesis of triptolide it was necessary to introduce the... [Pg.203]

Boron trifluoride etherate-Acetic anhydride. Youssefyeh and Mazur reported that the combination of the etherate and lithium bromide in acetic anhydride cleaves aliphatic ethers to the corresponding acetoxy compounds at room temperature. [Pg.39]

Boron trifluoride etherate-Acetic anhydride [1,72-73. before references]. [Pg.22]

Borabicyclo[3.3.1Jnonane (9-BBN), 31 Boric acid, 32 2-Bornene, 419 Boronobenzoic acid, 32 Boron oxide, 32 Boron tribromide, 33-34 Boron trichloride, 34-35 Boron triiluoride etherate, 7, 9, 35-36, 40, 124, 160, 161, 182, 229, 230, 430, 438 Boron trifluoride etherate—Acetic anhydride, 36-37... [Pg.260]

Ethers Acetyl p-toluenesulfonate. Boron tribromide. Boron trichloride. Boron trifluoride etherate—Acetic anhydride. Ferric chloride. Methylmagnesium iodide. Pyridine hydrochloride. Sodium borohydride. Sodium iodide. [Pg.513]

Ethyl-MgBr added to a stirred ice-cooled soln. of 6-dimethylamino-4,4-diphenyl-3-heptanol in dry ether, acetic anhydride in dry ether added, the mixture refluxed 0.5 hr., shaken overnight, poured into ice-cold dil. alkali, and isolated as hydrochloride 3-acetoxy-6-di-methylamino-4,4-diphenylheptane hydrochloride. Y 90%.— Acetylation in pyridine gave only a yield of 40%. (F. e. s. E. L. May and E. Mosettig, J. Org. Chem. 13, 459 (1948) method, see B.39, 1736 (1906).)... [Pg.318]

A previous report demonstrated that esters, alkyl halides, vinyl ethers, acetic anhydride and epoxides did not react under MBH reaction conditions or give intractable mixtures however, many kinds of electrophiles have been... [Pg.48]

Seven-membered Rings.—Clemmensen reduction of cyclohept-2-enone under anhydrous conditions, using amalgamated zinc and hydrochloric acid in diethyl ether-acetic anhydride solution, gives l-acetoxybicyclo[4,l,0]heptane (40... [Pg.226]

Compound 1 was converted by (1) benzoylation of the remaining hydroxyls, followed by either (2) selective transformation of 2-(trimethylsilyl)ethyl (SE) group at the reducing end into the corresponding P-acetate by treatment [4] with boron trifluoride etherate-acetic anhydride and (3) introduction of the methylthio group by treatment [5] with (methylthio)trimethylsilane and boron trifluoride, or (4) chemo-... [Pg.307]

When the reaction has subsided, boil the reaction-mixture under reflux for 2 hours then make it alkaline with sodium hydroxide solution, and distil it in steam until oily drops no longer come over in the aqueous distillate (1 2 litres). Extract the distillate thoroughly with ether ca. 150 ml.), and dry the ethereal extract over powdered sodium hydroxide. Filter the dry extract through a fluted filter-paper moistened with ether into a 200 ml. flask. Fit the flask with a distillation-head, or a knee-tube , and distil off the ether. Now replace the distillation-head by a reflux water-condenser, add 10 ml. of acetic anhydride, and boil the mixture under reflux for 10 15 minutes. [Pg.301]

Azlactone of a-acetylaminocinnamic acid. Warm a mixture of 29 g. of acetylglycine, 39-5 g. (37 -5 ml.) of redistilled benzaldehyde (Section IV,115), 15 g. of anhydrous sodium acetate and 67 g. (62 ml.) of acetic anhydride (95 per cent.) in a 500 ml. conical flask (equipped with a reflux condenser) on a water bath with occasional stirring until solution is complete (10-20 minutes). Boil the resulting solution for 1 hour, cool and leave in a refrigerator overnight. Stir the sohd mass of yellow crystals with 60 ml. of cold water, transfer to a Buchner funnel and wash well with cold water. (If the odour of benzaldehyde is stih apparent, wash with a little ether.) Recrystallise from carbon tetrachloride or from ethyl acetate-hght petroleum. The yield of azlactone, m.p. 150°, is 35 g. [Pg.909]

Acetoxylation and nitration. It has already been mentioned that 0- and m-xylene are acetoxylated as well as nitrated by solutions of acetyl nitrate in acetic anhydride. This occurs with some other homologues of benzene, and with methyl phenethyl ether,ii but not with anisole, mesitylene or naphthalene. Results are given in table 5.4. [Pg.88]

This is a way to do this procedure without having to use one of those crazy tube furnaces stuffed with thorium oxide or manganous oxide catalyst [21]. The key here is to use an excess of acetic anhydride. Using even more than the amount specified will insure that the reaction proceeds in the right direction and the bad side reaction formation of dibenzylketone will be minimalized (don t ask). 18g piperonylic acid or 13.6g phenylacetic acid, 50mL acetic anhydride and 50mU pyridine are refluxed for 6 hours and the solvent removed by vacuum distillation. The remaining residue is taken up in benzene or ether, washed with 10% NaOH solution (discard the water layer), and vacuum distilled to get 8g P2P (56%). [Pg.93]

Acetic Anhydride Acetone Benzyl Chloride Ethyl Ether HCI (Gas)... [Pg.284]

Perchloric acid Acetic acid, acetic anhydride, alcohols, antimony compounds, azo pigments, bismuth and its alloys, methanol, carbonaceous materials, carbon tetrachloride, cellulose, dehydrating agents, diethyl ether, glycols and glycolethers, HCl, HI, hypophosphites, ketones, nitric acid, pyridine, steel, sulfoxides, sulfuric acid... [Pg.1211]

Sodium peroxide Glacial acetic acid, acetic anhydride, aniline, benzene, benzaldehyde, carbon di-sulflde, diethyl ether, ethanol or methanol, ethylene glycol, ethyl acetate, furfural, glycerol, metals, methyl acetate, organic matter... [Pg.1212]

Bromoacetic acid can be prepared by the bromination of acetic acid in the presence of acetic anhydride and a trace of pyridine (55), by the HeU-VoUiard-Zelinsky bromination cataly2ed by phosphoms, and by direct bromination of acetic acid at high temperatures or with hydrogen chloride as catalyst. Other methods of preparation include treatment of chloroacetic acid with hydrobromic acid at elevated temperatures (56), oxidation of ethylene bromide with Aiming nitric acid, hydrolysis of dibromovinyl ether, and air oxidation of bromoacetylene in ethanol. [Pg.90]

Bisa.codyl, 4,4 -(2-PyridyLmethylene)bisphenol diacetate [603-50-9] (Dulcolax) (9) is a white to off-white crystalline powder ia which particles of 50 p.m dia predominate. It is very soluble ia water, freely soluble ia chloroform and alcohol, soluble ia methanol and ben2ene, and slightly soluble ia diethyl ether. Bisacodyl may be prepared from 2-pyridine-carboxaldehyde by condensation with phenol and the aid of a dehydrant such as sulfuric acid. The resulting 4,4 -(pyridyLmethylene)diphenol is esterified by treatment with acetic anhydride and anhydrous sodium acetate. Crystallisation is from ethanol. [Pg.201]

The synthesis of 2,4-dihydroxyacetophenone [89-84-9] (21) by acylation reactions of resorcinol has been extensively studied. The reaction is performed using acetic anhydride (104), acetyl chloride (105), or acetic acid (106). The esterification of resorcinol by acetic anhydride followed by the isomerization of the diacetate intermediate has also been described in the presence of zinc chloride (107). Alkylation of resorcinol can be carried out using ethers (108), olefins (109), or alcohols (110). The catalysts which are generally used include sulfuric acid, phosphoric and polyphosphoric acids, acidic resins, or aluminum and iron derivatives. 2-Chlororesorcinol [6201-65-1] (22) is obtained by a sulfonation—chloration—desulfonation technique (111). 1,2,4-Trihydroxybenzene [533-73-3] (23) is obtained by hydroxylation of resorcinol using hydrogen peroxide (112) or peracids (113). [Pg.491]

Many other polymerization processes have been patented, but only some of them appear to be developed or under development ia 1996. One large-scale process uses an acid montmorrillonite clay and acetic anhydride (209) another process uses strong perfiuorosulfonic acid reski catalysts (170,210). The polymerization product ia these processes is a poly(tetramethylene ether) with acetate end groups, which have to be removed by alkaline hydrolysis (211) or hydrogenolysis (212). If necessary, the product is then neutralized, eg, with phosphoric acid (213), and the salts removed by filtration. Instead of montmorrillonite clay, other acidic catalysts can be used, such as EuUer s earth or zeoHtes (214—216). [Pg.364]

Derivatives. Oxidation of pyrogaHol trimethyl ether with nitric acid, followed by reduction ia acetic anhydride and treatment of the product with aluminum chloride, affords 3,6-dihydroxy-2,4-dimethoxyacetophenone (228). 3,4,5-Trimethoxyphenol (antiarol) has been prepared by treatment of... [Pg.388]

In one process to produce highly activated cellulose for acetylation, cellulose is treated with NaOH (mercerization) followed by a hydroxyalkylating agent, eg, ethylene oxide or propylene oxide, to give a cellulose hydroxyalkyl ether with a DS of 0.05—0.3 (76). The resulting water-insoluble material is highly reactive to conventional acetic anhydride—sulfuric acid acetylation. [Pg.253]


See other pages where Ethers acetic anhydride is mentioned: [Pg.719]    [Pg.258]    [Pg.700]    [Pg.22]    [Pg.64]    [Pg.719]    [Pg.258]    [Pg.700]    [Pg.22]    [Pg.64]    [Pg.178]    [Pg.198]    [Pg.376]    [Pg.573]    [Pg.730]    [Pg.733]    [Pg.832]    [Pg.910]    [Pg.967]    [Pg.96]    [Pg.135]    [Pg.241]    [Pg.160]    [Pg.276]    [Pg.78]    [Pg.90]    [Pg.502]    [Pg.427]    [Pg.434]    [Pg.438]    [Pg.70]   
See also in sourсe #XX -- [ Pg.5 ]




SEARCH



Acetals ether

Acetic anhydride Boron trifluoride etherate

Acetic anhydride aromatic ethers acylation

Acetic anhydride with ethers

Acetic ether

Ethers cleavage with acetic anhydride

© 2024 chempedia.info