Phosphorus pentoxide, handling

Phenyl iso-thiocyanate, 642,643 Phenylthioureas, 422, 655 Phenylurea, 644, 645 Phenylurethanos, 264 Phloroacetophenone, 727, 736 Phosgene, 185 Phosphoric acid, 189, 284 Phosphorus, detection of, 1043 Phosphorus, red, purification of, 193 Phosphorus oxychloride, 367 Phosphorus pentabromide, 489, 492 Phosphorus pentachloride, 799, 822, 974 Phosphorus pentoxide, handling of, 407 Phosphorus tribromide, 189, 492 Phosphorus trichloride, 367 Phosphorus trisulphide," 836 Phthalamide, 983 Phthalein test, 681 ... 

Phosphorus pentoxide. This is an extremely efficient reagent and is rapid in its reaction. Phosphoric oxide is difficult to handle, channels badly, is expensive, and tends to form a syrupy coating on its surface after a little use. A preliminary drying with anhydrous magnesium... 

Place 45 g. of benzamide (Section IV, 188) and 80 g. of phosphorus pentoxide in a 250 ml. Claisen flask (for exact experimeutal details on the handling and weighing out of phosphoric oxide, see under Acetamide, Section 111,111). Mix well. Arrange for distillation (Fig.//, 29, 1 or Fig. II, 20, 1) under reduced pressure use a water pump with an air leak in the system so that a pressure of about 100 mm. is attained. Heat the flask with a free flame until no more liquid distils the nitrile will pass over at 126-130°/100 mm. Wash the distillate with a little sodium carbonate solution, then with water, and dry over anhydrous calcium chloride or magnesium sulphate. Distil under normal pressure (Fig. II, 13, 2 or II, 13, 6) from a 50 ml. flask the benzonitrile passes over as a colourless liquid at 188-189° (compare Section IV,66). The yield is 28 g. 

Phosphorus pentoxide must be handled with great care since it produces painful burns if allowed to come in contact with the skin. 

Methyl acetimidate hydrochloride, methyl glycinate hydrochloride, potassium tert-butoxide, and methyl formate were purchased from Aldrich Chemical Company, Inc., and were used without further purification. The checkers purchased methyl glycinate hydrochloride from Tokyo Chemical Industry Co. and potassium tert-butoxide and methyl formate from Kanto Chemical Co. Step A is very sensitive to moisture. Ethyl acetimidate hydrochloride is very hygroscopic. It must be dried before use in a desiccator over phosphorus pentoxide (P2O5) under reduced pressure and handled under argon. 

Phenylacetylene, 72 /ra X-TPHENYL-l,3-BUTAniENE, 75 a-PHENYL-a-CARBETHOXYGLUTARO-NITRILE, 80, 82 0-Phenylenediamine, 56, 86 a-Phenylglutaric acid, 82 a-PHENYLGLUTARIC ANHYDRIDE, 81 Phenylhydrazine, 90 Phenylmagnesium bromide, 97 Phenylsuccinic acid, 83 Phenylsuccinic anhydride, 85 Phosphoric acid, ortho-, 33, 34 Phosphoric anhydride, 33 Phosphorus oxychloride, Tl Phosphorus pentoxide, 22, 46 Potassium, 19, 20 directions for safe handling of, 20 Potassium lerl.-butoxide, solution of, 19... 

The corresponding reagents prepared from primary amines and phosphorus pentoxide were not easy to handle. Instead, a reagent mixture which was prepared from phosphorus pentoxide, primary amine hydrochloride, and N,N-dimethylcyclohexylamine was useful at 250 °C for the synthesis of N-substituted 2-aminoquinolines from the corresponding oxo compound [ 7 ]. ... 

Hazards Use great care when handling 99% nitric acid produces poisonous reddish-brown fumes of nitrogen oxides use maximum ventilation. Wear gloves when handling phosphorus pentoxide causes skin irritation. 

The needed apparatus and chemicals are placed in the dry box, and the box is closed and thoroughly flushed with dry oxygen-free nitrogen. When in use, it is kept under a small nitrogen pressure so that air will not diffuse into the box. A dish containing phosphorus pentoxide is often placed inside the dry box to ensure that moisture is removed, and if it is particularly important to remove all traces of water and oxygen, a dish containing the liquid sodium-potassium alloy may be placed inside the box. This alloy must, however, be handled with considerable care, for it will bum in air and will react explosively with water. 

Phosphorus pentachloride, 31, 48, 104 Phosphorus pentoxide, 30, 22, 46 Phosphorus trichloride, 31, 88, 111 Potassium, 30, 19, 20 directions for safe handling of, 30, 20 Potassium 4-amino-3,5-dinitrobenzene-sulfonate, 31, 46... 

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