Propane, 2-Bromide

Water in propane NFM 41-004 Change in color of cobalt bromide... 

Usually, iodides and bromides are used for the carbonylation, and chlorides are inert. I lowever, oxidative addition of aryl chlorides can be facilitated by use of bidcntatc phosphine, which forms a six-membered chelate structure and increa.scs (he electron density of Pd. For example, benzoate is prepared by the carbonylation of chlorobenzene using bis(diisopropylphosphino)propane (dippp) (456) as a ligand at 150 [308]. The use of tricyclohexylphosphine for the carbonylation of neat aryl chlorides in aqueous KOH under biphasic conditions is also recommended[309,310]. 

S-Acetylthiocholine bromide [25025-59-6] M 242,2, m 217-223°(dec), It is a hygroscopic solid which can be recrystd from ligroin-EtOH (1 1), dried and kept in a vacuum desiccator. Crystn from C H -EtOH gave m 227° or from propan-l-ol the m was 213°. [Acta Chem Scand 11 537 1957, 12 1481 7958.]... 

S-Butyryl thiocholine iodide [(2-butyrylmercaptoethyl)trimethyl ammonium iodide] [1866-16-6] M 317.2, m 173", 173-176". Recrystd from propan-l-ol and dried in vacuo store in the dark under N2. The bromide has m 150° (from Me2CO) or m 140-143° (from butan-l-ol). [Gillis Chem and Ind (London) 111 1957 Hansen Acta Chem Scand 11 537 1957.]... 

Enby 6 is an example of a stereospecific elimination reaction of an alkyl halide in which the transition state requires die proton and bromide ion that are lost to be in an anti orientation with respect to each odier. The diastereomeric threo- and e/ytAra-l-bromo-1,2-diphenyl-propanes undergo )3-elimination to produce stereoisomeric products. Enby 7 is an example of a pyrolytic elimination requiring a syn orientation of die proton that is removed and the nitrogen atom of the amine oxide group. The elimination proceeds through a cyclic transition state in which the proton is transferred to die oxygen of die amine oxide group. 

Use of the Hammond Postulate requires that the reverse reactions both be fast. Obtain energies for the transition states leading to 1-propyl and 2-propyl radicals ipropane+Br end and propane+Br center), and draw a reaction energy diagram for each (place the diagrams on the same axes). Is use of the Hammond Postulate justified Compare the partial CH and HBr bond distances in each transition state to the corresponding distances in propane and hydrogen bromide, respectively. Does the Hammond Postulate correctly predict which bond distances will be most similar Explain. 

To a well stirred suspension of 9 g of sodium phenyl acetate and 2.4 g of magnesium turnings in 25 cc of anhydrous ether, a solution of 9.4 cc of isopropyl bromide in 50 cc of anhydrous ether are added. The mixture is refluxed for one hour (during which time propane is evolved) and then 5 cc of cyclopentanone in 25 cc of anhydrous ether are added dropwise. The mixture is then refluxed for one hour and poured over ice water containing some hydrochloric acid. The ether solution is separated and extracted with 200 cc of 5% sodium hydroxide. The alkaline solution on acidification gives the free acid which is filtered off, dried in a desiccator and recrystallized from a mixture of ethylene dichloride and petroleum ether. 

Diacetoxy acetophenone 1 -p-Methoxyphenyl-2-benzylamino propane Hydrogen bromide... 

At 03C, a solution of 120 mg (1.2 mmol) of phenylacetylene in 2 mL of dry Et20 is treated with 0.45 mL (1.2 mmol) of 2.6 M BuLi in hexane, The mixture is stirred for 30 min, then a solution of 290 mg (1.3 mmol) of anhyd zinc bromide in 2 mL of Et20 is added. After cooling to —78 C, 100 mg (0.6 mmol) of 2-(ben-zyloxy)propanal (7) are added and the reaction mixture is allowed to warm to 0 C over a 2-h period. The reaction is quenched with sat. aq NH4C1. The organic layer is separated, dried over Na2S04 and concentrated. The residual oil is purified by column chromatography on silica gel yield 154 mg (95%) d.r. (syn/anti) 95 5 (determined by HPLC). 

Die Reduktion von Benzil liefert bei Gegenwart von Methylchlorid, -bromid, -jodid oder -tosylat als Hauptprodukt 2-Methoxy-J-oxo-1,2-diphenyl-propan neben cis- und trans-1,2- Dimethoxy-1,2- diphenyl-dthylen ... 

The same goes for propane and butane. Nitrogen oxide, hydrogen halides, and vinyl bromide stabilise acetylene, but sulphur dioxide destabilise it. 

Ethoxylated methylcarboxylates Propoxyethoxy glyceryl sulfonate Alkylpropoxyethoxy sulfate as surfactant, xanthan, and a copolymer of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate Carboxymethylated ethoxylated surfactants (CME) Polyethylene oxide (PEG) as a sacrificial adsorbate Polyethylene glycols, propoxylated/ethoxylated alkyl sulfates Mixtures of sulfonates and nonionic alcohols Combination of lignosulfonates and fatty amines Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride Anionic sodium dodecyl sulfate (SDS), cationic tetradecyl trimethyl ammonium chloride (TTAC), nonionic pentadecylethoxylated nonylphenol (NP-15), and nonionic octaethylene glycol N-dodecyl ether Dimethylalkylamine oxides as cosurfactants and viscosifiers (N-Dodecyl)trimethylammonium bromide Petrochemical sulfonate and propane sulfonate of an ethoxylated alcohol or phenol Petrochemical sulfonate and a-olefin sulfonate... 

A variation of this procedure devised by Galik and Landa81 starts with propane-1,1,3,3-tetracarboxylate (58) instead of 54. LAH reduction of 58 affords the alcohol (59). After converting 59 to the bromide (60), 51 is obtained... 

Vinyl and Aryl Halides and Triflates. The organosilane reduction of aryl halides is possible in high yields with triethylsilane and palladium chloride.195 The reaction is equally successful with aryl chlorides, bromides, and iodides. Aryl bromides and iodides, but not chlorides, are reduced with PMHS/Pd(PPh3)4 in moderate to excellent yields.199 This system also reduces vinyl bromides.199 p-Chlorobenzophenone is reduced to benzophenone with yym-tetramethyldisilo-xane and Ni/C in excellent yield (Eq. 59).200 There is a report of the organosilane reduction of aryl and vinyl triflates in very high yields with the combination of Et3SiH/Pd(OAc)2/dppp (l,3-bis(diphenylphosphino)propane) (Eq. 60).201... 

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