Ammonium organic extractions

A solution of 6.3 g (0.9 moles) ethoxyacetylene in 50 ml ether is added dropwise during 30 min to a Grignard reagent prepared from 2.18 g (90 mg-atoms) magnesium and 9.81 g (90 mmoles) ethyl bromide. The reaction mixture is stirred for 1 hr at room temperature and then a solution of 3 g (9 mmoles) 3) -acetoxyandrost-5-en-I7-one in 50 ml dry ether is added dropwise. The mixture is refluxed for 1 hr and after cooling to 0° poured into 100 ml of an aqueous ammonium chloride solution. The aqueous solution is extracted with ether, and the organic extract is washed with ammonium chloride solution and water, dried, and evaporated. The residue is chromatographed on 130 g alumina (activity III). Elution with petroleum ether-benzene (1 1) yields, after crystallization from acetone-hexane, 1.27 g (35%) 3j5-acetoxy-17a-ethoxyethynylandrost-5-en-17) -ol mp 138-139° Ho -122°. 

To a solution of dihydronaphthalene 41 (250 mg, 0.77 mmol) in CH2CI2 (5 mL) was added methyl trifluoromethanesulfonate (227 mg, 1.38 mmol). The mixture was stirred at rt until the starting material had been completely consumed as judged by TLC analysis (3 h). The mixture was cooled to 0°C and a solution of NaBHt (111 mg, 2.92 mmol) in 4 1 MeOH THF (3 mL) was slowly added. The mixture was warmed to rt then quenched with saturated aqueous ammonium chloride (50 mL). The resulting mixture was extracted with CH2CI2 (3 X 50 mL) and the combined organic extracts were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The resulting material was dissolved in 4 1 THF/H2O (5 mL) and oxalic acid (485 mg, 3.85 mmol) was added. The reaction... 

The solution obtained is treated with ammonium hydroxide (d = 0.92 106 cc), saturated with sodium chloride, and then extracted with ethyl acetate (total 660 cc). The combined organic extracts are washed with a saturated aqueous sodium chloride solution (60 cc) and then dried over sodium sulfate. The volatile products are evaporated under reduced pressure (20 mm Hg) and a mixture of 1-(2-acetoxypropyl)-2-methyl-4-nltrolmidazole and 1-(2-acetoxypropyl)-2-methyl-5-nitroimidazole (18.6 g) is obtained in the form of a red oil. 

To a solution of hexamethyldisilane (2.5 mmol) in HMPA (CAUTION— CANCER SUSPECT AGENT) (3 ml) at 0-5 °C was added methyl lithium (2.5 mmol, 1.5 m MeLi.LiBr complex in ether) dropwise. After being stirred for 3 min, the red solution was treated with Cul (2.5 mmol) in Me2S (1 ml), the resulting black reaction mixture was stirred for 3 min. and 2,3-dibromo-propene (1 mmol) was added rapidly via a syringe. The reaction mixture was allowed to warm to room temperature, and was stirred for 1.5 h. It was then poured into pentane (25 ml) and saturated ammonium chloride solution (25 ml, buffered to pH 8 by the addition of ammonium hydroxide), and the mixture was stirred vigorously for 1 h. The aqueous phase was re-extracted with pentane, and the combined organic extracts were dried. Removal of... 

Initially, 50 was converted into the benzoxazinone 51 by reaction with phosgene in the presence of triethylamine and 51 was isolated in 95% yield upon crystallization from methanol. Deprotection of the pMB group from 51 was accomplished with ceric ammonium nitrate (CAN) in aqueous acetonitrile. Efavirenz was isolated in 76% yield after crystallization from EtOAc-heptane (5 95), as shown in Scheme 1.19. There were two issues identified in this route. First, lequiv of ani-saldehyde was generated in this reaction, which could not be cleanly rejected from product 1 by simple crystallization to an acceptable level under the ICH guideline. Anisaldehyde was removed from the organic extract as a bisulfite adduct by washing with aqueous Na2S205 twice, prior to the crystallization of 1. Secondly,... 

Oxone (10.86 g, 17.7 mmol) in H20(45 ml) is stirred withTBA-HS04 (30 g, 88 mmol) for 30 min at room temperature. The aqueous solution is extracted with CH2CI2 (3 x 70 ml), and the dried (MgS04) organic extracts are evaporated to give the ammonium salt (89%). 

The reaction mixture is cooled in a water-ice bath, and a saturated aqueous ammonium chloride solution is added at such a rate as to maintain the temperature below 35°C. Ammonium chloride solution is added in portions until addition produces no further exothermic reaction (Note 3). The supernatant solution is decanted through glass wool onto 400 g of ice in a 4-L separatory funnel. The residual solids are washed with three portions of hexane, approximately 1000 nt total, and the washes are decanted into the separatory funnel. After the phases are separated, the aqueous phase is washed with an additional 500-mL portion of hexane. The combined organic extracts are washed with 500 nl of saturated ammonium chloride, and then with 500 nl. of brine. The organic layer is dried over anhydrous magnesium sulfate and filtered. Most of the solvent is removed by a rotary evaporator and the residual oil is distilled at reduced pressure using an ice water-cooled fraction cutting head. After a small forerun, approximately 390-392 g (94% of theory) is collected as a colorless oil, bp 116°C/1.6 nm (lit. 155°C/17 rim). ... 

Vanadium usually is recovered from its ores by one of two processes, (1) leaching raw mineral with hot dilute sulfuric acid, and (2) roasting ore with common salt to convert vanadium into water soluble sodium vanadates. In the sulfuric acid leaching process, vanadium is extracted from acid leach liquors by solvent extraction with an aliphatic amine or an alkyl phosphoric acid in kerosene. The organic solvent extract then is treated with an aqueous solution of ammonia in the presence of ammonium chloride to convert vanadium into ammonium metavanadate. Alternatively, the organic extract is treated with dilute sulfuric acid or an aqueous solution of soda ash under controlled conditions of pH. Vanadium is precipitated from this solution as a red cake of sodium polyvanadate. 

To the precipitate was added dichloromethane, and then the combined organic extracts were filtered and concentrated in vacuo to afford the corresponding azacrown ether-type quaternary ammonium salt (0.27 g, 85%) as a light brown crystalline solid. The purity of the cmde product is high enough to be used in the catalysis experiments, m.p. 118-119 °C [a]p 71 (c= 1.0, CHCI3). 

The principle Zr ore, zircon (Zr silicate) is processed by caustic fusion or by direct chlorination of milled coke and zircon mixts. Washing of the Na fusion cake leave an acid soluble hydrated Zr oxide, whereas chlorination yields mixed Si and Zr tetrachlorides which are separated by distillation. Removal of the Hf from the Zr takes place through counter current liq-liq extraction (Ref 33), For this purpose the oxide or the tetrachloride is dissolved in dil hydrochloric acid to which ammonium thiocyanate is added as a complexing agent. The organic extracting phase is methyl isobutylketone... 

The epoxide la (1.5 g, 10 mmol) and ammonium acetate (1.15 g, 15 mmol) were admixed in a Pyrex test tube and subjected to microwave irradiation for 40 s. After complete conversion, as indicated by TLC, the reaction mass was diluted with water (20 mL) and extracted with ethyl acetate (2 x 25 mL), washed with brine (20 mL) and dried over Na2S04. The organic extract was purified by column chromatography on silica gel (Aldrich 100-200 mesh, hexane-ethyl acetate, 7 3) affording 2a (1.25 g, 75% yield) as an oily liquid. 

To a stirred solution of (+)-6-ethyl-5-methyl-2-(4-sulfotolyl-l,3-dimethyl-but-l-ene)-yl-3,6-dihydro-2H-pyran (54.4 mg, 0.15( mmol) in dry Et20 (1 ml) cooled to 0°C was added dropwise a solution of nBuLi (1.5 M in hexane, 0.18 mmol). The yellow solution was stirred at 0°C for 10 min, then at -42°C for 15 min. Dry hexane (0.5 ml) was added, and a solution of the methyl (8E,10S,llS,12S)-2,3-di-O-benzyl-l,4-dideoxy-ip-[ll-methyl-12-formylcyclopropylethenyl]-D-glucoheptopyranuronate (60.0 mg, 0.125 mmol) in Et20 (0.5 ml) was added dropwise. The reaction mixture was stirred at -42°C for 2 h, then quenched with ammonium chloride, and extracted with EtOAc several times. The combined organic extracts were washed with brine, dried over sodium sulfate, and the solvent removed in vacuum. The residue was chromatographed over silica gel (hexane-EtOAc, 8 2) to give 53.7 mg (51%) of a mixture of diastereomers. The mixture was used in the next reaction without further purification. 

A mixture of 4 parts of 2-iminothiazoline, 8.3 parts of bromomethyl-2-thienylketone and 40 parts of absolute ethanol is stirred and refluxed for 2 hours in a water-bath. After cooling, the precipitated hydrobromide is filtered off. From this salt the free base is liberated on treating with ammonium hydroxide solution and it is extracted with chloroform. The organic extract is separated, treated with activated charcoal, filtered and the filtrate is first dried over magnesium sulfate and then evaporated. The solid residue is recrystallized from 24 parts 2-propanol, to yield 2-imino-3-[(2-thienylearbonyl)-methyl]-thiazoline MP 117.5°-118.5°C. 

A solution of 60.0 g (0.182 mole) this ester in 550 ml absolute ethanol was treated with 91.6 g (1.45 moles) of ammonium formate. The reaction mixture refluxed for 5.0 hours. Then it was cooled, concentrated, and partitionated in a separatory funnel between 200 ml dichloromethane and 150 ml water. The aqueous phase was extracted three times with 50 ml portions of dichloromethane. The organic extracts were collected, dried over anhydrous sodium sulfate, and evaporated. 50 g (0.182 mole, 100%) 3-amino-4-carbomethoxy-2,5-dihydro-2-thiophenevaleric acid methyl ester was obtained as a colorless oil. 

---