Acetone, bromo preparation

Preparation of 9, 11 -Epoxy-17a-21 -Dihydroxy-16 -Methyl-4-Pregnene-3 0-Dione 21-Acetate To a stirred solution of 100 mg of the 9a-bromo-11(3,17a,2Ttrihydroxy-16 3-methyl-4-pregnene-3,20-dione 21-acetate in 3 ml of tetrahydrofuran and 1 ml of methanol under nitrogen was added 1.02 ml of 0.215 N methanolic sodium methoxide. After 10 minutes at 25°C, 0.2 ml of acetic acid was added and the methanol removed in vacuo. The residue was acetylated with 1.00 ml of pyridine and 0.5 ml of acetic anhydride at 60°C for 70 minutes. The mixture was taken to dryness in vacuo, water added, and the product extracted into chloroform. The residue was crystallized from ether-acetone to give pure 9(3,11 (3-epoxy-17a,21-dihydroxy-16(3-methyl-4-pregnene-3,20-dione 21-acetate. 

Several 5,6-disubstituted-3-azido[l,2,4]triazine-l-oxides 1021 were prepared (77JHC1221) by treatment of 1020 with nitrous acid. 3-Azido[l, 2,4]-triazine-2-oxide 1023 was prepared by reacting the corresponding 3-bromo derivative 1022 with either tetramethylguanidinium azide in chloroform or sodium azide in aqueous acetone. These azido derivatives were proven to exist in the open-chain form by H- and l3C-NMR and 1R spectra (77JHC1221) (Scheme 191). 

Available from K K Laboratories or may be prepared in 89% yield by the following procedure. To a solution of 393 g. (2.63 moles) of sodium iodide in 1 1. of reagent grade acetone is added 394 g. (2.50 moles) of l-bromo-3 chloropropane (Aldrich Chemical Co.). After stirring 2 hours at room temperature, the mixture is filtered, the sodium bromide is washed with acetone, and the acetone is evaporated at reduced pressure. A dark iodine color is present along with some solid sodium salts. The oil is dissolved in ether, and the solution is washed with a 10% aqueous sodium thiosulfate solution. The ethereal layer is separated, dried over anhydrous sodium sulfate, and evaporated at reduced pressure to yield 454 g. of an oil that can be used without further purification. 

Phenylacetylene has been prepared by the elimination of carbon dioxide from pbenylpropiolic acid by means of phenol1 or aniline 2 or by heating with barium hydroxide 3 from styrene dibromide, by heating with potassium hydroxide in alcohol 4 by heating /3-bromo or chloro styrene with sodium ethylate or potassium hydroxide in alcohol 5 by passing the vapors of a-dichloroethylbenzene over hot soda lime 6 by the action of alcoholic potassium hydroxide on dibenzal-acetone tetra-... 

Alkyl- and aryl-hydrazones of aldehydes and ketones readily peroxidise in solution and rearrange to azo hydroperoxides [1], some of which are explosively unstable [2], Dry samples of the p-bromo- and p-fluoro-hydroperoxybenzylazobenzenes, prepared by oxygenation of benzene solutions of the phenylhydrazones, exploded while on filter paper in the dark, initiated by vibration of the table or tapping the paper. Samples were later stored moist with benzene at —60°C to prevent explosion [3], A series of a-phenylazo hydroperoxides derived from the phenyl-or p-bromophcnyl-hydrazones of acetone, acetophenone or cyclohexanone, and useful for epoxidation of alkenes, are all explosive [4], The stability of several substituted phenylazo hydroperoxides was found to be strongly controlled by novel substituent effects [5],... 

Synthesis ofLysergic Acid, By reacting N-benzoyl-3-(B-carboxyethyl)-dihydroindole (see JCS, 3158 (1931) for the preparation of this compound) with thionyl chloride, followed by aluminum chloride gives l-benzoyl-5-keto-l,2,2a,3,4,5-hexahydrobenzindole. This is then brominated to give the 4-bromo-derivative, which is converted to the ketol-ketone by reacting with methylamine acetone ethylene ketol. This is then hydrolized by acid to yield the diketone and treated with sodium methoxide to convert it to the tetracyclic ketone. Acetylate and reduce this ketone with sodium borohydride to get the alcohol, which is converted to the hydrochloride form, as usual. 

The condensation of 2-(5-bromo-4-chloro-2-hydroxybenzoyl)pyridine 506 in a sealed tube with ammonia and acetone proved a convenient route to 2//-l,3-benzoxazine derivative 225 via the imine intermediate 507 <1996CPB734>. The yield was improved considerably and a closed vessel was not required for the reaction when the ammonia was prepared in situ from NH4I and piperidine, and 2,2-dimethoxypropane was used instead of acetone (Scheme 95). The improved method was extended to the preparation of other 2,2-disubstituted-2//-l,3-benzoxazine derivatives <2001T7501>. 

SYNTHESIS A solution of 13.0 g of 3-bromo-N-cyclohexyl-4,5-dimethoxy-benzylidenimine (see under MP for its preparation) in 125 mL anhydrous Et20 in a He atmosphere was cooled with an external dry ice acetone bath to -80 °C with good stirring. To this clear pale yellow solution there was added 32 mL 1.55 M butyllithium in hexane (about a 25% excess) which was stirred for 10 min producing a fine white precipitate. There was then added 7.0 g diethyl disulfide. The dry ice bath was removed and the reaction stirred as it came to room temperature. This was... 

SYNTHESIS A solution of 11.5 g 3-bromo-N-cyclohexyl-4,5-diethoxy-benzylidenimine (see under ASB for its preparation) in 150 mL anhydrous Et20 was placed in a He atmosphere, well stirred, and cooled in an external dry ice acetone bath to -80 °C. There was light formation of fine crystals. There was then added 25 mL of 1.6 N butyllithium in hexane and the mixture stirred for 15 min. This was followed by the addition of 5.8 g diethyl disulfide over the course of 20 min during which time the solution became increasingly cloudy with the eventual deposition of an insoluble gummy phase. The mixture was allowed to come to room temperature over the course of 1 h, and then added to 400 mL of dilute HC1. The organic phase was separated and stripped of solvent under vacuum. This residue was combined with the original aqueous phase, and the mixture was heated on the steam bath for... 

SYNTHESIS A solution of 13.4 g 3-bromo-N-cyclohexyl-4-methoxy-5-ethoxy-benzylidenimine (see under ME for its preparation) in 150 mL anhydrous Et20 was placed in a He atmosphere, well stirred, and cooled in an external dry ice/acetone... 

Dissolve 1.0 g of the compound in 10-15 ml of glacial acetic acid, cautiously add a solution of 3-4 ml of liquid bromine in 10-15 ml of glacial acetic acid until the colour of bromine persists and allow the mixture to stand for 15-20 minutes. Pour into 50-100 ml of water, filter off the bromo compound at the pump and wash with a little cold water. Recrystallise from dilute ethanol. Alternatively dissolve 1.0 g of the phenol in water, ethanol or acetone and add slowly, with constant shaking, just sufficient of a bromine solution (prepared by adding 5g of bromine to a solution of 7.5 g of potassium bromide in 50 ml of water) to impart a yellow colour to the mixture. Allow to stand for 5 minutes. Add about 50 ml of water, and shake vigorously to break up any lumps. Filter and wash the bromo derivative with a dilute solution of sodium metabisulphite. Recrystallise from ethanol or from dilute ethanol. 

Preparation of N-(3-chloropropyl)-N -[2-(l,3-dioxanyl)-ethyl]-piperazine A solution of 30 g (0.15 mol) of N-[2-(l,3-dioxanyl)-ethyl]-piperazine and 11.8 g (0.075 mol) of l-bromo-3-chloropropane in 150 ml of dry benzene was refluxed with stirring for 5 hours. After cooling, the N-[2-(l,3-dioxanyl)-ethyl]-piperazinium bromide which had precipitated was filtered off, the filtrate was concentrated in vacuo and the residual oil was distilled. 14.1 g (68%yield) of N-(3-chloropropyl)-N -[2-l,3-dioxanyl)-ethyl]-piperazine which occurred as a light yellow oil were obtained. Boiling point 152°C to 155°C under 0.07 mm Hg (nD23 = 1.49 40). The disuccinate prepared in acetone and recrystallized from acetone melts at 104°C to 105°C on a hot stage microscope. 

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