Nitrogen flushing

Synthesis of Alkviamines. General Procedures. Method (A). The synthesis of p-phenethylamine is representative. A flame dried, nitrogen-flushed, 100 ml flask, equipped with a septum inlet, magnetic stirring bar and reflux condenser ivas cooled to 0°C. Sodium borohydride (9.5 mmol, 0.36 g) was placed in the flask followed by sequential addition of THF (13-15 ml) and BF3-Et20 (12 mmol, 1.5 ml) at 0°C. After the addition, the ice bath was removed and the contents were stirred at room temperature for 15 min. The solution... 

Irradiation of 9-nitroanthracene under conditions in which gaseous products are continuously removed by nitrogen flushing results in the formation of anthraquinone monooxime in addition to the above products ... 

Triphenylphosphine, recrystallized from ethanol, 3.72 g (14.3 mmole) is added under nitrogen flush to 35 mL of dry THF in a 250-mL, two necked, round-bottomed flask fitted with a nitrogen inlet tube, dropping funnel, and magnetic stirrer. Dry purified CuCl,2 0.473 g (4.78 mmole) is added under nitrogen flush to this solution. The solution is first homogeneous and colorless, but after 1 minute of stirring, a thick white precipitate forms. 

To a 500 ml dry, nitrogen-flushed resin kettle equipped with a mechanical stirrer, thermometer, condenser with drying tube, dropping funnel, and heating mantle are added 34.8 gm (0.20 mole) of 2,4-toluene diisocyanate and 0.12 gm... 

A nitrogen-flushed Schlenk flask was charged with bis(l,5-cyclooctadiene)nickel(0) (3.2 mmol) and bipyridal (3.2 mmol) and then refluxed under nitrogen. Thereafter the mixture was treated with 10 ml of dimethylfuran, 1,5-cyclooctadiene, and toluene and then stirred for 30 minutes at 80°C. The mixture was then treated with a mixture of the step 5 product (1.0 mmol) and the step 2 product (1.0 mmol) dissolved in 10 ml of toluene and heated for 4 days at 80°C. Thereafter the mixture was cooled to 60°C and precipitated in hydrochloric acid/methanol, 1 1.2, respectively. The precipitate was isolated, redissolved in CHC13, and then reprecipitated in method, and 0.4 g product isolated having an Mn of 120,000 Da. 

Charge all items in a suitable stainless steel vessel and mix. Keep nitrogen flushing through-... 

Filter through 0.22-micron filter previously sterilized and fill in presterilized amber-colored bottle with nitrogen flushing. 

Dissolve item 1 in nitrogen-flushed cold item 13 (25° to 30°C) by using stirrer. 

Do not produce vortex. Make up the volume to 1 L with nitrogen-flushed item 13. 

B. Preparation of 4-Amino-1,2,5,6-tetrahydro-l-phenyl-phosphorin-3-carbonitrile. To a nitrogen-flushed 1-1. threenecked flask equipped with a mechanical stirrer, a pressure-equalizing addition funnel, and a reflux condenser are added 25 g. (0.22 mole) of potassium room temperature, 250 ml. of water is added, and the resulting mixture is stirred for 30 minutes while the product crystallizes. The mixture is filtered, and the solid product is washed on the filter with two 50-ml. portions of cold ethanol to give, after drying at 78° (1 mm.), 36-38 g. (84-88%) of 4-amino-1,2,5,6-tetrahydro-1 -phenylphosphorin- 3-carboni-trile, m.p. 134.5-137° (Note 9). A small amount of product can be recovered from the filtrate (Note 10). 

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