Dimethylaminoethyl acetate

The log (rate) vs. log (time) curves for the McLafferty rearrangement in the molecular ions of n-butyl acetate, 2-phenylethyl acetate, 2-phenyl-propyl acetate and 2-dimethylaminoethyl acetate have been found to be approximately parallel to each other and the rates at any time decreased significantly on going from n-butyl acetate to 2-phenylethyl acetate to... 

It may now be asked what further structural modifications of the acetylcholine and muscarine molecules are compatible with the possession of strong acetylcholine-like activity. The data are only semi-quantiative, pending laborious experimental work. This is because the activity of each substance is made up of two factors, the efficacy and the affinity (see p. 293). Thus the cation of dimethylaminoethyl acetate 12,73), which is the unquaternized analogue of acetylcholine (12.65), has been described as having almost no muscarinic... 

Experiments with model substrates support the conclusions derived from inhibitor studies. For example, dimethylaminoethyl acetate has been compared with acetylcholine as a substrate for cholinesterase. The essential difference between these substrates is the strength of the... 

Fig. 37. The relative rate is the rate of hydrolysis of dimethylaminoethyl acetate compared with the rate of hydrolysis of acetylcholine at the same pH. From Wilson. ...

Dimenhydrinate. Dimenhydrinate [523-87-5] (Dramamine) (18) is a white crystalline, odorless powder that melts between 102 and 107°C. It is sparingly soluble in water, freely soluble in ethanol and chloroform, and sparingly soluble in diethyl ether. Dimenhydrinate is prepared by combining dimethylaminoethyl ben2hydryl ester with 8-ch1orotheophy11ine and refluxing in an isopropyl alcohol solution. The crystalline precipitate of dimenhydrinate that forms on cooling is collected by filtration, washed with cold ethyl acetate, and dried. 

The crystalline precipitate of /3-dimethylaminoethyl benzohydryl ether 8-chlorotheophyl-linate is collected on a filter, washed with ether and dried. It melts at 96°-99°C. It is dissolved in boiling ethyl acetate, filtered hot to remove any insoluble material, and then chilled. The salt so obtained melts at 102.5°104°C after filtration, washing with ether and drying. 

A different approach, although stdl working with essentially non-fiinctional polymers has been exemplified [114,115], in which, a 100% solid (solvent free) hot melt has been irradiated to produce pressure-sensitive adhesives with substantially improved adhesive properties. Acrylic polymers, vinyl acetate copolymers with small amounts of A,A -dimethylaminoethyl methacrylate, diacetone acrylamide, A-vinyl pyrrohdone (NVP) or A A have been used in this study. Polyfunctional acrylates, such as trimethylolpropane trimethacrylate (TMPTMA) and thermal stabilizers can also be used. 

Ethyl-a-Keto-y-dimethylaminobutyrate p-Acetylphenylhydrazone. (JMC, 7, 144 (1966)). 40 g of p-aminoacetophenone in 250 ml of water and 143 ml of coned hydrochloric acid is diazotized at 0-5° with 21 g of sodium nitrite in 200 ml of water. To the resulting solution is added 60.3 g of ethyl a-(2-dimethylaminoethyl)aceto-acetate followed by 63 g of sodium acetate. Raise the pH to 6.5 and maintain with the addition of 3 N NaOH (also use the 3 N for the initial raise to 6.5). Stir, with external cooling for 2 hours, make basic, and extract with three 400 ml portions of ehloroform. Combine the extracts and dry over sodium sulphate, eoneentrate in vacuo. Crystallize the residue with a mixture of benzene-petroleum ether, after purification with charcoal, to get 65 g. Crystallize two more times to get a melting point of 84-85°. 

To a solution of previously dried l-[[2-carboxy-3-(2-dimethylaminoethyl)-5-indolyl]methanesulphonyl]-pyrrolidine (1.6 g 0.0442 moles) in anhydrous quinoline (75 ml) and under atmosphere of nitrogen, cuprous oxide (160 mg 0.0011 moles) was added. The reaction mixture was heated to 190°C for 15 minutes, stirred to room temperature, poured into a mixture of 1 N hydrochloric acid (150 ml) and ethyl acetate (50 ml), shaken and decanted. The aqueous solution was washed several times with ethyl acetate, then solid sodium bicarbonate was added until pH = 7.8, and washed with n-hexane to eliminate the quinoline. The aqueous solution was made alkaline with solid potassium carbonate and extracted with ethyl acetate. The organic solution was dried (Na2S04), the solvent removed under reduced pressure when a dark oil was obtained (1.3 g yield 92%). This product was purified by column chromatography with silica gel and methylene chloride ethanol ammonium hydroxide (60 8 1) as eluent and a white foam (0.8 g) of l-[[3-(2-dimethylaminoethyl)-5-indolyl]methanesulphonyl]-pyrrolidine was obtained. To a solution of the above product (0.8 g) in acetone (30 ml), a few drops of hydrogen chloride saturated dioxan solution, were added. The precipitated solid was collected by filtration, washed with acetone and dried to give l-[(3-(2-(dimethylamino)ethyl)-5-indolyl)methanesulphonyl]-pyrrolidine hydrochloride (0.75 g). Melting point 218°-220°C. 

The 2-dimethylaminoethyl 1-adamantanecarboxylate was mixed with 1-bromodecan and allowed to stand for about 6 weeks. The resultant crystalline mass was washed with ether and dried to gave 2-(l -adamantanecarbonyloxy)ethyldimethyldecylammonium bromide as white crystals, melting point 183°-184.5°C (two recrystallizations from ethyl acetate). 

A mixture of 24.5 g 9-(2-dimethylaminoethyl)-9-hydroxymethyl-10-(methylacridan) 1 L of m-xylene and 125.0 g phosphorus pentoxide are refluxed for 3 h the reacture mixture is cooled, poured on to ice, agitated for 15 min, alkaline by the addition of sodium hydroxide solution, and extracted with ethyl acetate the organic phases are washed with water, dried over magnesium sulfate, and dried by vacuum distillation. The residue is dissolved in ether, filtered, and concentrated to a small volume pentane is added with distillation to remove the ether. The mixture is filtered and concentrated to about 100 ml crystallization is allowed to commence and the mixture is... 

To a solution of 1.4 g (24.9 mmoles) of KOH in 10 ml of ethanol was added 2.8 g (7.8 mmoles) of (S)-3-(2- dimethylaminoethyl)-5-[2-oxo-l,3-oxazolidin-4-ylmethyl]-lH-indol-2-carboxylic acid ethyl ester. The resulting solution was heated at reflux temperature for one hour. It was cooled and the solvent evaporated to dryness. The residue was dissolved in 6 ml of water and washed three times with 10 ml of dichloromethane. The aqueous solution was cooled to 5°C, adjusted to pH 6 with glacial acetic acid, stirred for 30 minutes at that temperature and the water evaporated to dryness. The residue was redissolved in 30 ml of water and 5 g of ionic exchange resin (Dowex50WX8-400) added. The mixture was left under stirring at room temperature for 24 hours. The resin was filtered and it was washed with water. For desorbtion the resin was suspended with 20 ml of a 10% aqueous solution of ammonia and stirred at room temperature for 5 hours. After that it was filtered and washed with water, water was evaporated to dryness under reduced pressure to give 7.75 g (94%) of the title acid as a yellow crystalline solid. Melting point 230°C. 

A suspension of 30 g of sodium hydride in benzene (30 ml) was added dropwise to 52 g of 8-chlorodibenzo[b,f]thiepin-10(llH)-one dissolved in dimethylformamide (800 ml), and the mixture was heated at 100°C for 2 hours. To this, there were added 68 g of 2-dimethylaminoethyl chloride, and the mixture was heated at 60°C for 39 hours. The reaction mixture, after cooled, was poured into ice-water, and the solution was extracted with ethyl acetate. The ethyl acetate layer, after washed with water, was extracted with 10% hydrochloric acid, when oil was precipitated. The aqueous layer, in which oil was precipitated, was washed with ether, made neutral with concentrated sodium hydroxide solution and then extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried over magnesium sulfate, and concentrated to give oil, which was allowed to stand to provide solid. The solid was washed with petroleum ether and recrystallized from cyclohexane to yield 42.5 g of 8-chloro-10-(2-dimethylaminoethyl)-oxydibenzo[b,f]thiepin as crystals, melting point 90°C to 91°C. Maleate as colorless needle, melting point 204°C to 204.5°C. 

Evidence that aminonitriles and 2-aminoindoles are the intermediates in this cycli-zation leading to indoles was obtained with a-substituted 2-nitrophenylacetonitriles. The final absorption of 1 mol of hydrogen was slow in the hydrogenation of 42, ammonia was not formed, and the aminonitrile 43 was the product, which cyclized to the oxindole 44 in the presence of acid. The hydrogenation of P-dimethylaminoethyl-sub-stituted nitronitrile 45 over 10% Pd-C in ethyl acetate at 80°C afforded ammonia and the indole 46. However, the hydrogenation of 45 over 8% Pd-C in acetic acid at 80°C did not result in the formation of an appreciable amount of ammonia, and a crystalline dihydrochloride corresponding to an amidine structure 47 could be prepared from the product (Scheme 9.17). 

The synthesis of bufotenine itself followed closely upon the proof of its structure. Hoshino and Shimodaira reduced the ethyl ester of 5-ethoxy-indole-3-acetic acid by the Bouveault-Blanc procedure to the corresponding primary alcohol, which was treated with phosphorus tribromide and then dimethylamine, to give the ethyl ether of bufotenine, which was demethylated with aluminum chloride (130). In a later synthesis, 2,5-dimethoxybenzyl cyanide (XXIII) was alkylated by Eisleb s method with dimethylaminoethyl chloride in the presence of sodamide to give l-(2,5-dimethoxyphenyl)-3-dimethylaminopropyl cyanide (XXIV), which was then hydrogenated over Haney nickel to yield 2-(2,5-di-methoxyphenyl)-4-dimethylaminobutylamine (XXV R = Me). De-methylation of this with hydrobromic acid, followed by oxidation of the product (XXV R = H) with potassium ferricyanide yielded bufotenine (XIX) via the related quinone (109). 

Figure 29 Separation of the nonsteroidal anti-inflammatory drugs ibuprofen (peak 1), naproxen (2), ketoprofen (3), and suprofen (4) in anion-exchange CEC mode using a strong anion-exchange monolithic column. Conditions on-column alkylated monolith prepared from mixtures consisting of 8% 2-dimethylaminoethyl methacrylate, 24% 2-hydroxyethyl methacrylate, 8% ethylene dimethacrylate, 20% cyclohexanol, 40% 1-dodecanol UV-initiated polymerization at room temperature for 16 h cfpmode= 1423 nm. Column dimensions inner diameter 0.1 mm, total length 335 mm, effective length 250 mm. Mobile phase 0.4 mol/L acetic acid and 4 mmol/L triethylamine in acetonitrile/methanol (60/40), voltage -25 kV, injection -5 kV for 5 s, temperature 50°C, UV detection at 250 nm. (Reprinted from Ref. 127, with permission.)...

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