Hexaethylphosphorous triamide

Hexaethylphosphorous triamide, 46, 33 Hexamethylenetetramine, 46, 3 in synthesis of isophthalaldehyde from a,i/- Iiair ino m xylene, 47, 76 Hexametiiylpiiosphorous triamide, 46, 42... 

Caution All operations should be performed in a well ventilated hood. Hexaethylphosphorous triamide is potentially toxic and should be handled with protective gear. 

Hexaethylphosphorous triamide (97%) was obtained from the Aldrich Chemical Company, Inc., and used as received. It can be prepared from diethylamine and phosphorus trichloride following the literature procedure.3... 

Hexaethylphosphorous triamide (= HEPT) Diethylamide, N,N, N"-phosphinidynetris-(8) Phosphorous triamide, hexaethyl- (8,9) (2283-11-6)... 

Hexaethylphosphorous triamide 2 may be substituted for the methyl homolog without adverse effect on the quality and yield of the product. 

Trifluoromethyltrimethylsilane, (CH3)3SiCF3 (1). The reagent is prepared from BrCF3, ClSi(CH3)3, and hexaethylphosphoric triamide in 65-70% yield.1... 

A solution of bromine (31.5 mmol) dissolved in 20 ml acetonitrile was cooled to — 15°C and hexaethylphosphorous triamide (34.1 mmol) added at such a rate the temperature was kept below 10°C. When the addition was completed sodium azide (34.2 mmol) was added and the resulting suspension allowed to warm to ambient temperature over 2 hours. The mixture was re-cooled to — 15°C and dimethyl-2-oxopropyl phosphate (28.6 mmol) and DBU (0.65 mmol) added. The solids were filtered off after 45 minutes, washed with acetonitrile, cyclopropanecarboxaldehyde (24.5 mmol) dissolved in 200 ml methyl alcohol containing K2CO3 (57.8 mmol) added, and the mixture stirred at ambient temperature 16 hours. The mixture was cooled to 0°C, diluted with 250 ml ice-cold water, and the product extracted 3 times with 30 ml n-octane. The extracts were combined, dried, and the product isolated in 73% yield. 

Much more advanced and effective appeared to be the method reported recently by Beaucage et al. [127]. Starting from ( )-2-amino-l-phenylethanol (88) the authors performed chemoselective N-acylation with ethyl fluoroacetate (89) providing 90, followed by its reaction with hexaethylphosphorous triamide (Scheme 23). Cyclic N-acylphosphoramidite 91 has been obtained as a mixture of diastereomeric rotamers. Condensation of AT4-benzoyl-5 -0-DMT-2 -deoxy-cytidine 92 with 91 in the presence of lH-tetrazole gave, after silica gel chromatography, pure Rc,RP-93 and Sc,SP-93.31P NMR studies indicated that when Rp-93 or Sp-93 was reacted with 3 -0-acetyl-AT-benzoylcytidine (94) and A ATjN jN -tetramethylguanidine (TMG), the dinucleoside phosphotriester was formed in nearly quantitative yield with full P-stereospecificity. After subsequent sulfurization, the P-stereodefined dinucleoside phosphorothioate tri-... 

Hexadiyne-l,6-diol, 186 Hexaethylbenzene, 826, 828, 1133 Hexaethylphosphorous triamide, 425 Hexafluoro-2-butyne, 425-426... 

Hexachlorocyclotriphosphazatriene (Phosphonitrilic chloride) (I) [1, 425, before Hexaethylphosphorous triamide]. Mol. wt. 346.99, m.p. 113-115°. Supplier Albright and Wilson, Birmingham, England. 

Desulfurization Hexaethylphosphorous triamide. Methyl iodide. Nickel boride. Nickel catalysts (a) Raney type. Nickel peroxide. 

Hexadiene-l-ol, 465 Hexaethylphosphorous triamide, 207 Hexafluoroacetone, 119 Hexafiuoro-2-bulyne, 207 Hexafluorophosphoric acid, 402 1,4,5,8,9,10-Hexahydroanthracene, 338... 

Hexaethylphosphorous triamide [Tris(diethylamino)phosphine. (C2H5)2N3P] [I, 425, before references]. 

In another example of the new process, which involves loss of C02 and S,5 thio-benzilic acid,7 is condensed with a ketone, for example cyclohexanone, to give an oxathiolan-5-one (5) in high yield. p-Toluenesulfonic acid or boron trifluoride is used as catalyst. When (5) is heated with hexaethylphosphorous triamide (1, 425), the corresponding olefin (6) is obtained in good yield. 

An exothermic reaction usually begins after all the hexaethylphosphorous triamide is introduced, and some of the bromotrifluoromethane escapes through the bubbler. 

H2O2, cat Na2Mo04 2H20, ceit Hg(OAc)2, cat hexaethylphosphoric triamide... 

Dithioles and Related Systems. - Base-catalysed condensation of the 1,2-dithiolium salt (195) with ethylidenemalononitrile yields the dithiole (196). The action of potassium borohydride on the enamine (197) results in the rearranged thiopyranthione (199), presumably via compound (198). Deprotonation of the bisulphate (200) or heating the tosylhydrazone (201) produces the thienothiophen (202). It has been reported that the dihydrodithiolone (203) is desulphurized by hexaethylphosphoric triamide to yield the thietanone (204). 1,2-Dithiole-3-thiones (205 X = S =... 

An ethereal soln. of hexaethylphosphorous triamide added with stirring at -20° to a soln. of phenyl azidoformate in the same solvent, and after 10 min. cooled to -70° to precipitate the product -> phosphazide deriv. Y 74.5%. F. e. s. K. Pilgram, F. Gorgen, and G. Pollard, J. Heterocyclic Chem. 8, 951 (1971). 

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