2-bromo- ethanol recrystallization

Bromo-2-nitrophenylacetic acid (26 g, 0.10 mol) was dissolved in a mixture of 50% HjSO (400 ml) and ethanol (600 ml) and heated to 90°C. Over a period of 1 h, zinc dust (26.2 g, 0.40 mol) was added. slowly and then heating was continued for 2 h. The excess ethanol was removed by distillation. The solution was cooled and filtered. The filtrate was extracted with EtOAc. The filtered product and extract were combined, washed with 5% NaCOj and brine and then dried (MgSO ). The solvent was removed in vacuo and the residue recrystallized from methanol to give 20.5 g (97% yield) of the oxindole. 

To a solution of 14.5 g of 2-bromo-2 -(2-chlorobenzoyl)acetanilide in 100 ml of tetrahy-drofuran, an excess of liquid ammonia (ca 150 ml) was added. The ammonia was kept refluxing with a dry-ice condenser for 3 hours after which time the ammonia was allowed to evaporate and the solution was poured into water. Crystals of 2-amino-2 -(2-chloro-benzoyOacetanilide were collected, which after recrystallization from ethanol melted at 162° to 164 C. 

A solution of 44 grams of 2-bromo-4 -benzyloxypropiophenone and 44 grams of 2-(4-meth-oxyphenyDethylamine in 270 ml of ethanol was refluxed for 3 hours. Then the ethanol was distilled off in vacuo and the concentrate mixed with ether. The resulting crystallizate was Sucked off after which the filtrate was mixed with an excess of 2 N hydrochloric acid. As a result of this the hydrochloride of 4 -benzyloxy-2-[2-(4-methoxyphenyl)ethylamino]-propiophenone slowly crystallized. This substance was also Sucked off, washed with water and alcohol, and dried in vacuo. After recrystallization from dilute alcohol the yield was 25.5 grams of a product with a melting point of 217 to 218°C. 

Recrystallization of 2-bromo-(3-nitro-4-benzyloxyphenyl)ethanol Materials and equipment... 

C. 2,3-Diamino-5-bronto pyridine (Note 8). A 100-ml. flask fitted with a reflux condenser is charged with 10.9 g. (0.05 mole) of 2-amino-5-bromo-3-nitropyridine, 30 g. of reduced iron, 40 ml. of 95% ethanol, 10 ml. of water, and 0.5 ml. of concentrated hydrochloric acid (Notes 9 and 10). The mixture is heated on a steam bath (Note 11) for 1 hour, and at the end of this period the iron is removed by filtration and is washed three times with 10-ml. portions of hot 95% ethanol. The filtrate and washings are evaporated to dryness, and the dark residue is recrystallized from 50 ml. of water, 1 g. of activated carbon being used and the mixture being filtered while hot. The charcoal is washed with hot ethanol to avoid losses. 2,3-Diamino-5-bromopyridine crystallizes as colorless needles, m.p. 163°. The yield is 6.5-7.1 g. (69-76%). 

N-Acetyl-l-4-bromo-2,5-dimethoxyamphetamine. A slight excess of bromine water is added to a solution of 3.0 g of the above drug (N-acetyl-1-2,5-dimethoxyamphetamine) in 30 ml of dioxane, and the solution is stirred for 6 hours. The solvent is removed by evaporation, leaving the title compound, which is recrystallized from ethanol. Yield 3.0 g, mp 153-155°. 

A) IE 4-Bromo-2,5-dimethoxyamphetamine Hydrochloride. A suspension of N-acetyl-1-4-bromo-2,5-dimethoxyamphetamine (2.5 g) in 60 ml of hydrochloric acid and 60 ml of water is heated at reflux temperature for 18 hours during which time the N-acetyl compound will dissolve. Unreacted starting material can be removed and the filtrate evaporated to give a yellow solid that is recrystallized from ethanol-ether to give the product as clear solid. Yield ... 

Methoxy-2-Naphthol. A mixture of 10 g of 6-bromo-2-methoxynaphalene, 0.5 g of copper bronze, 8.5 g of NaOH, and 175 cc of water are shaken in a suitable high pressure vessel at 200° for 75 minute. Cool, dilute with a little water, filter copper off, and acidify with coned HCl acid. Collect the resulting product, wash with water and dry in air. Recrystallize the resulting crude product with dilute ethanol to get a little over 5 g. 

A flask containing 1.0 gm (0.00235 mole) of 2-bromo-1,1,3,3-tetraphenyl-propene, 2.0 gm (0.0357 mole) of potassium hydroxide, and 30 ml of ethanol is heated to reflux for 1 hr. After this time, the reaction mixture is cooled, diluted with water, the solid filtered and then recrystallized from ethanol acetone (2 1) to afford 0.81 gm (100%), m.p. 165°C. 

Bromo-6-hydroxynaphthalene (0.45 mol) and imidazole (1.10 mol) were dissolved in 300 ml of N, iV-di meth I formamide and then treated with /-butyl-dimethylsilyl chloride (0.53 mol) and stirred at ambient temperature overnight. The mixture was then poured into water and the precipitate isolated. After washing with water and cold ethanol, it was recrystallized from ethanol and 97.2 g of product isolated as off-white crystals, mp = 62-64°C. 

Butyl lithium (50 ml, 1.65 mol in hexane) was added under nitrogen to a stirred suspension of 2,6-dibromopyridine (19.5 g) in dry ether (200 ml) at -50°C. After 0.75 h a solution of 4-tolunitrile (10.0 g) in ether (50 ml) was added stirring was continued at -50°C for 3 h. The mixture was allowed to warm to -30°C and treated with hydrochloric acid (200 ml, 2 mol). The precipitated solid was collected, washed with water to give the 2-bromo-6-(4-toluoyl)pyridine as colourless needles (12.2 g), melting point 97°-98°C (recrystallized from aqueous ethanol). 

I). A solution of trans-3-bromocinnamoyl chloride (12.3 g) in anhydrous toluene (150 ml) was added slowly with stirring to a solution of ethylamine (10 g) in dry ether (100 ml) at room temperature. The reaction mixture was heated at reflux for 1 hour, and the solvent and excess amine were then removed under reduced pressure. The residue was triturated with water, filtered, and recrystallized from ethanol-water to give trans-3-bromo-N-ethylcinnamamide, m.p. 89-90°C, as a white crystalline material. NMR and IR spectra as well as elemental analysis were consistent with the assigned... 

A mixture of the crude oil of methyl 2-bromo-3- 4-[2-(5-ethyl-2-pyridyl)ethoxy]phenyl propionate (73.0 g) thiourea (14.2 g), sodium acetate (15.3 g) and ethanol (500 ml) was stirred for 3 hours under reflux. The reaction mixture was concentrated under reduced pressure, and the concentrate was neutralized with a saturated aqueous solution of sodium hydrogencarbonate, to which were added water (200 ml) and ether (100 ml). The whole mixture was stirred for 10 min to yield 5- 4-[2-(5-ethyl-2-pyridyl)ethoxy]benzyl -2-imino-4-thiazolidinone as crystals (0.3 g, 523.0%). Recrystallization from methanol gave colorless prisms, melting point 187°-188°C, dec. 

Tetrahalocobaltate(II) salts are prepared in a manner similar to that used for the manganese compounds. The chloro and bromo derivatives are recrystallized from absolute ethanol, the solutions being evaporated to obtain the crystals. 

A mixture containing 50 g. (0.15 mole) of anthracene dibromide, 250 ml. of toluene, and 0.5 g. of phenol is allowed to stand for 4 days in a flask protected from the atmosphere with a calcium chloride tube. The reaction mixture is heated slowly to 50° and after 2 hours at this temperature is heated on a boiling water bath for 30 minutes. The toluene is removed by steam distillation, and the resulting solid is recrystallized from 1250 ml. of ethanol to give a 94% yield of 9-bromo-anthracene, m.p. 98-99°. A product melting at 100-101° is obtained in 55% yield by distillation under reduced pressure followed by five recrystallizations from petroleum ether (b.p. 90-100°) and one from a large volume of ethanol. 

Ozone is bubbled through a stirred solution of 4-bromo-l-vinylimidazolc-5-carbonitrile (0.5 g, 2.53 mmol) in methanol (30 ml) at —78°C until TLC analysis shows complete reaction (30 min). Dimethyl sulfide (0.2 ml, 0.17 g, 2.72 mmol) is added, and the mixture is allowed to waum up to room temperature and stirred (1 h). Distillation of the solvent under reduced pressure gives the product (0.35 g, 80%) as a white solid after recrystallization from aqueous ethanol, m.p. 142-144°C. 

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