Hexamethylphosphoramide hydride

Hexamethylphosphoramide (HMPA) was distilled from calcium hydride and stored over molecular sieves before use. 

Hexamethylphosphoramide Phosphoric triamide, hexamethyl- (8,9) (680-31-9) Diisobutylaluminum hydride Aluminum, hydrodiisobutyl- (8) Aluminum, hydrobis(2-methylpropyl)- (9) (1191-15-7)... 

Hexamethylphosphoramide is dried by distillation from calcium hydride. 

Hexamethylphosphoramide was purchased from the Fisher Scientific Company and the Aldrich Chemical Company, Inc. It was distilled from calcium hydride prior to use. 

BASF AG CRBPII dba DBN DBU DIBAL-H DMAP DMF DMF-DMA DMPU HMDS HMPA HMPT H-LR LDA LDE LRAT MCPBA MOM NMO NMP PCC PhH = Badische Anilin- Soda Fabrik AG = cellular retinol-binding protein type II r dibenzylideneacetone = 1,5-diazabicyclo[4.3.0]non-5-ene = l,8-diazabicyclo[5.4.0]undec-7-ene = diisobutylaluminium hydride = 4-dimethylaminopyridine = A V-dimethylformamide = A,V-dimethylformamide, dimethylacetal = 1,3 -dimethyl-3,4,5,6-tetrahydro-2( 1H)-pyrimidone = hexamethyldisilazane = hexamethylphosphoramide = hexamethylphosphorous triamide = Hoffmann-La Roche = lithium diisopropylamide = lithium diethylamide = lecithin retinol acyltransferase = m-chloroperbenzoic acid = methoxymethyl = iV-methylmorpholine oxide = l-methyl-2-pyrrolidinone = pyridinium chlorochromate = benzene... 

Sodium 0,0-diethyl phosphorotelluroate, 485 Sodium dithionite, 485 486 Sodium-Ethanol, 472 Sodium-Hexamethylphosphoramide, 473 Sodium hydride-Sodium /-amyl oxide-Zinc chloride, 486... 

A solution of 2.57 g of l-(2, 4 -dichlorophenyl)-2-(N-imidazolyl)ethanol in 10 ml of hexamethylphosphoramide was dropped at 25°C into a suspension of 0.52 g of sodium hydride (50% in oil) in 5 ml of hexamethylphosphoramide. When hydrogen emission was over, the salification was completed by heating for 1 hour at 50°C. After cooling to 25°C, 2.58 g of l-chloromethyl-4-phenylthiobenzene were added. The temperature was raised to 50°C and maintained at that temperature for 12 hours. At the end of the reaction, the mixture was poured into 200 ml of water, the product was extracted with diethyl ether, the solvent was evaporated off and the residue was purified twice on a silica gel column, using ethyl acetate as eluant and testing the various fractions by TLC. The solvent was evaporated off the middle fractions... 

Chemicals AIBN CAN DIBAL DMAP DMSO HMPA LAH LDA mCPBA NBS NCS or PCC PDC Py TBAF TEMPO a.a -azobislisobutyronitrile) cerium(IV) ammonium nitrate diisobutylaluminium hydride 4-(dimethylamino)pyridine dimethyl sulfoxide hexamethylphosphoramide lithium aluminum hydride lithium diisopropylamide m-chloroperoxybenzoic acid A-bromosuccinimide A-chlorosuccinimide superoxide anion radical pyridinium chlorochromate pyridinium dichromate pyridine tetrabutylammonium fluoride 2,2,6,6-tetramethyl-l-piperidinyloxy free radical... 

Metal hydride reduction of methyl dehydroabietate (64b) afforded alcohol (65) whose tosyl derivative on heating with sodium iodide and zinc in dimethylformamide yielded (66). The use of hexamethylphosphoramide gave an inferior yield of (66). Regio and stereoselective acetoxylation with Pb(OAc)4 in acetic acid at 100°C gave only 30% yield of (67) but the same experiment realized with Pb(OAc)4 using a Hg medium-pressure lamp at room temperature yielded (67) in 74%. The H NMR spectrum of (67) showed that the OAc group was introduced in 7a-position. This on subjection to acid-catalyzed 13-elimination (EtOH/10% HC1) produced (68) in quantitative yield. 

AD-mix-P 9-BBN Bn Boc Bz BOM CDI m-CPBA CSA Cy DBU DDQ DEAD DIAD DIBAL-H DIPT DME DMF DMAP DMSO EDC HMPA HOBT KHMDS LDA MEM MOM MoOPH NaHMDS NBS NMM NMO Piv PMB Reagent for Sharpless asymmetric dihydroxylation 9-Borabicyclo[3.3.1 ]nonyl Benzyl t-Butoxy carbonyl Benzoyl B enzyloxy methyl Carbonyldiimidazole m-Chloroperoxybenzoic acid Camphorsulfonic acid Cyclohexyl 1,8 -Diazabicy clo[5.4.0] undec-7-ene 2,3 -Dichloro-5,6-dicyano-p-benzoquinone Diethyl azodicarboxylate Diisopropyl azodicarboxylate Diisobutylaluminum hydride Diisopropyl tartrate Dimethoxyethane A,N-Dimethylformamide 4-Dimethylaminopyridine Dimethyl sulfoxide N-(3-Dimethylaminopropyl)-A -ethylcarbodiimide Hexamethylphosphoramide 1 -Hydroxybenzotriazole Potassium hexamethyldisilazane Lithium diisopropylamide Methoxyethoxymethyl Methoxymethyl Oxidodiperoxymolybdenum(pyridine)(hexamethylphophoramide) Sodium hexamethyldisilazane N - Bromosuccinimide A-Methylmorpholine A-Methylmorpholine A-oxide Pivaloyl /j-Methoxybenzyl... 

Pentane and trichloroethylene were distilled from calcium chloride, tetrahydrofuran from the sodium ketyl of benzophenone, and hexamethylphosphoramide from calcium hydride under reduced pressure. 

O. 414 mole) and magnesium turnings (I I g., 0.458 g.-atom) is added 146 ml. (0.828 mole) of dry hexamethylphosphoramide (dried by distillation from calcium hydride). The resulting solution is blown over under a nitrogen atmosphere into the 500-ml. dropping funnel. The solution is slowly run into the cooled suspension where the methiodide salt dissolves. When the addition is complete, the reaction mixture is stirred at room temperature overnight. 

The oxazolidone tosylate 101 with sodium hydride in benzene at 55°C gives the aziridine 102 (48%). This aziridine reacts with sodium p-cresolate in hexamethylphosphoramide to yield two products. Attack of the anion at C5 of the aziridine 102 forms the oxazinone 103, while attack at C6 leads to the oxazolidinone 104. 

Econazole nitrate may be synthesised by the reaction pathway shown in Figure 12. This reaction scheme, taken from Godefroi et al, has optional pathways at each stage. Imidazole is coupled with brominated 2,4-dichloroaceto -phenone and the resultant ketone is oxidized with sodium borohydride to the corresponding alcohol. This product is coupled with 2,4-dichlorotoluene by means of sodium hydride in hexamethylphosphoramide (an aprotic solvent) before being extracted with nitric acid to give econazole nitrate. 

HMPA, hexamethylphosphoramide, is toxic and a cancer-suspect agent. It was purchased from Tokyo Kasei Kogyo Co. or Aldrich Chemical Company, Inc. and distilled from calcium hydride under reduced pressure before use. When dimethylpropyleneurea (DMPU) was used in place of HMPA, none of the desired bis(trimethy silyl)benzene was obtained. 

Phenyllithium, and 50% sodium hydroxide with a catalytic amount of TEBA chloride, or cetrimonium bromide have been used in a few instances, instead of sodium hydride, to generate the anion in alkylation reactions. A study comparing the use of lithium diisopropylamide in tetrahydrofuran/hexamethylphosphoramide, potassium hydroxide with benzene and dicyclohexyl-18-crown-6, and 50% sodium hydroxide with benzene or acetonitrile and cetrimonium bromide for alkylation concludes that the phase transfer procedure is advantageous. Triton B has sometimes been used as an alternative to aqueous hydroxide for the hydrolysis of 27 to 28, " particularly in cases where R = 2-nitrobenzyl. - - ... 

To N-methylaniline added first dropwise at 65° to stirred sodium hydride in xylene containing hexamethylphosphoramide (1 equiv.) after 1/4 h, 1,2,4-trimethoxybenzene in xylene and mixture at 85 ° (6 h) to afford Me... 

Titanium, tetrakis(trimethysilyl)oxy-, 334 Titanium complexes alloy hydrides, 353 amino adds, 342 antimony, 345 arsenic, 345 bromides, 357 chlorides, 355, 356 fluorides, 354 Group IV derivatives, 352 halides, 354 electron spectra, 358 hexamethylphosphoramide, 335 iodides, 357... 

The reaction of trispentailuorophenylmethane with sodium or lithium hydride under an argon atmosphere in hexamethylphosphoramide at 20— 25 °C gives a solution of the trispentafluorophenyl carbanion [(C F, C ] (c/ p. 392), the n.m.r. spectrum of which has been described. It seems probable that bispentafluorophenyl carbanions are involved in the formation of 1,1,2,2-tetrakispentafluorophenylethane from bispentafluorophenylmethyl bromide and cyanide ion, triphenylphosphine, or butyl-lithium, and their failure to carbonate during the last reaction at - 70 °C has been attributed to their relatively high stability. ... 

All of the aromatic ketones and silanes were used as purchased from commercial sources. Tetrahydrofuran (THE) was purified prior to use by first drying over calcium hydride, then fractionally distilling. Alternatively, THE was distilled under nitrogen from sodium naphthalene complex. N,N,N, N -Tetramethylurea (TMU) was dried over calcium hydride and then fractionally distilled, while hexamethylphosphoramide was used as purchased. Magnesium metal was used in the form of 30 mesh shot. 2,3,5,6-Tetrachloro-1,4-benzoquinone used in the kinetic studies was recrystallized from acetone prior to use. Toluene, p-xylene, and benzene were dried by refluxing over calcium hydride followed by fractional distillation. Octamethylcyclotetra-siloxane (D ) was dried and purified by distillation at atmospheric pressure. The first and last fractions were discarded and the center fraction, boiling at 175-176°C, was used. Karstedt s catalyst was obtained from General Electric Silicone Products Business Division.Eiltrol-20 was used as purchased from the Eiltrol Company. Styrene monomer was freed from... 

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