Black reaction mixture

To a mixture of 100 ml of THF and 0.10 mol of the epoxide (note 1) was added 0.5 g Of copper(I) bromide. A solution of phenylmagnesium bromide (prepared from 0.18 mol of bromobenzene, see Chapter II, Exp. 5) in 130 ml of THF was added drop-wise in 20 min at 20-30°C. After an additional 30 min the black reaction mixture was hydrolysed with a solution of 2 g of NaCN or KCN and 20 g of ammonium chloride in 150 ml of water. The aqueous layer was extracted three times with diethyl ether. The combined organic solutions were washed with water and dried over magnesium sulfate. The residue obtained after concentration of the solution in a water-pump vacuum was distilled through a short column, giving the allenic alcohol, b.p. 100°C/0.2 mmHg, n. 1.5705, in 75% yield. 

To a mixture of 0.10 mol of 1-ethoxy-l,2-heptadiene (see this chapter, Exp. 13) and 120 ml of diethyl ether was added 1 g of copper(I) bromide. A solution of butyl magnesium bromide in about 200 ml of diethyl ether, prepared from 0.25 mol of butyl bromide (see Chapter II, Exp. 5) was added in 15 min. The reaction was weakly exothermic and the temperature rose slowly to about 32°C. The mixture was held for an additional 40 min at that temperature, then the black reaction mixture was... 

D. s-Aaetyl-2(3B)-oxaaolone. The crude mixture of 3-acety1 4- and 5-chloro-2-oxazolidinone from Step C is placed in a 2-L, three-necked flask equipped with a thermometer, sealed mechanical stirrer, and gas discharge tube. The material is heated to 120°C with stirring, and the temperature is then slowly increased to 150 C and held there until the evolution of gas ceases (Note 10). The cooled, black reaction mixture is distilled at 20 nm. The fractions boiling up to 150°C are collected and redistilled through a 50-cm X 3-cm Vigreux column fitted with a variable take-off head. There is obtained 140-172 g (55-68%) of product, bp 108-112°C (24 mm), which solidifies, rap 35-37°C (Note 11). 

Similarly, indole itself could be converted by 2-methylsulfanyl-l,3-dithiolium iodide to its 3-dithiolium derivative, which gave 27 quantitatively with DBU. However, treatment of indoles, which bear the benzo-dithiolium moiety in the 2-position with tertiary amines, resulted in a black reaction mixture. All attempts to isolate the o-quinoid compound 28 failed (Scheme 7). 

Acetyl-5-deoxy-l,2-0-isopropylidene-[3-iJ - threo - pent - 4 - enofura-nose (34). (1) From 3-0-acetyl-5-deoxy-5-iodo-1,2-0-isopropylidene- -d-xylofuranose (31). Anhydrous silver fluoride (7.5 grams) was added to a solution of 7.2 grams 26 in dry pyridine (50 ml.), and the mixture shaken at room temperature for 24 hours. The black reaction mixture was diluted with ether (50 ml.), and the supernatant liquid was decanted from the dark, inorganic residue. The residue was further extracted with ether (3 X 50 ml.) and the pyridine-ether solution partially decolorized... 

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... 

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), and the resulting black reaction mixture was stirred for 3 min. Ether (6 ml)... 

HC=CC=CLi and CH3C=CC CLi (in THF-hexane) unexpectedly gave very intractable black reaction mixtures. 

The reaction mixture is cooled to 5-10° in an ice-salt bath (Note 3), and, with continued stirring, a solution of 31.7 g. (21.3 ml., 0.250 mole) of oxalyl chloride in 200 ml. of dry carbon disulfide is added through the dropping funnel in the course of 20 minutes. After the addition is complete, the thick black reaction mixture is allowed to warm to room temperature, refluxed for 1 hour, and then cooled to 0-5° in an ice bath. The mixture is stirred throughout these steps. One hundred grams of chipped ice is added with stirring, followed by 400 ml. of cold water. Steam is then passed into the flask until the carbon disulfide and unreacted dimethylaniline are removed, and the green-black... 

When both flasks have cooled down, the black reaction mixture is cautiously added to the sodium hydroxide solution. It is added in small portions, then swirled around to mix it. They react together quite violently. The reaction here is sodium hydroxide reacting with hydrochloric acid to produce table salt, with formic acid to produce sodium formate, and with methamphetamine hydrochloride to produce methamphetamine free base. When the sodium hydroxide solution gets very hot, the chemist stops adding the reaction mixture to it until it cools down again. 

After all the black reaction mixture has been added to the sodium hydroxide solution, there is a brown liquid layer floating above the sodium hydroxide solution. This brown layer is methamphetamine free base. It also has a good deal of unreacted methamphetamine hydrochloride dissolved in it. This latter has to be neutralized because it will not distill in its present form. The 1000 ml flask is stoppered and shaken vigorously for 5 minutes. This gets the methamphetamine hydrochloride into contact with the sodium hydroxide so it can react. 

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