Methylene bromide chloride

In a 1-litre three-necked flask, mounted on a steam bath and provided respectively with a separatory funnel, mechanical stirrer and double surface condenser, place 165 g. of bromoform (96 per cent.). Add 10 ml. of a solution of sodium arsenite made by dissolving 77 g. of A.R. arsenious oxide and 148 g. of A.R. sodium hydroxide in 475 ml. of water. Warm the mixture gently to start the reaction, and introduce the remainder of the sodium arsenite solution during 30-45 minutes at such a rate that the mixture refluxes gently. Subsequently heat the flask on the steam bath for 3-4 hours. Steam distil the reaction mixture (Fig. 11, 41, 1) and separate the lower layer of methylene bromide (79 g.). Extract the aqueous layer with about 100 ml. of ether a further 3 g. of methylene bromide is obtained. Dry with 3-4 g. of anhydrous calcium chloride, and distil from a Claisen flask with fractionating side arm. The methylene bromide boils constantly at 96-97° and is almost colourless. 

The reaction itself works by the action of Na or K from NaOH or KOH which form what is called a catechoxide dianion with the two OHs of the catechol species. This makes the two ripe for an attack by a methylene halide which can be either DCM (methylene chloride, or dichloromethane), DBM (methylene bromide, or di-bromomethane) or DIM (methylene iodide, or diiodomethane). DCM is cheap and works pretty well, but DBM and DIM work better yet are more expensive. 

Allyl chloride A 36 Dipropyl ether B 65 Methylene bromide A... 

Methyldinitrophenol, d715, d716 Methyl enanthate, m266 Methylene bromide, dl 10 Methylene bromochloride, b305 Methylene chloride, d235... 

Methylene blue, 9 517-518 Methylene bromide, 4 348 Methylenecarbenes, 21 144, 146 Methylene chloride, 16 371-380 analytical methods for, 16 376 binary azeotropes of, 16 373t chlorocarbon/chlorohydrocarbon of industrial importance, 6 227t consumption, 6 244t dry, 16 372... 

Methylene chloride also acts as a coupling reagent but is less effective than methylene bromide. Examples of coupling material containing structure are shown in Table II. 

When the reaction was repeated using methylene chloride (3.0 mL) instead of methylene bromide, the polymer had values of [q] 0.49 dl/g and OH 0.134. 

Dithiomethane, see Bromochloromethane, Methylene bromide. Methylene chloride... 

T- (Methylenebis (thio))bis-ethane, see Phorate Methylene bromide, see Bromoform Methylene chloride, see Carbon tetrachloride. Chloroform... 

Methyl -propyl ketone, 340 Methyl pyridines, purification of, 177-179 N-Methylpyrrole, 837, 838 Methyl red, 621, 625 sodium salt of, 626 Methyl salicylate, 780,782 Methyl sulphite, 304 2-Methylthiophene, 836 Methyl p-toluenesulphonate, 825 Methylurea, 968, 969 Methylene bromide, 300 Methylene chloride, purification of, 176 3 4-Methylenedioxycinnamic acid, 711, 719... 

Compounds such as methylene chloride or methylene bromide (73ACS779, 72ACS1258, 63USP3086016) or tris(chloromethyl)amine (74LA1851), which can be treated as formaldehyde precursors or substitutes, have also been used for the preparation of hexahydro-1,2,4,5-tetrazines (377). 

Propane and cyclopentane give isopropyl chloride and cyclopentyl chloride, respectively, whereas isobutane is transformed to ferf-butyl chloride under the same reaction conditions (yields are 69%, 74%, and 76%, respectively). Neopentane undergoes isomerization to yield 2-chloro-2-butane (88%). When saturated, hydrocarbons were allowed to react with methylene bromide and SbF5 bromoalkanes were obtained in comparable yields (64-75%). Formation of the halogenated product can be best explained by the mechanistic pathway (I) depicted in Scheme 5.55. Since SbF5 always contains some HF, mechanism (II) may also contribute to product formation (Scheme 5.55). 

Methylene-2-azetidonones, 536 Methylene bromide-zinc-titanium(IV) chloride, 337-338... 

M ETHYLENATION Dimethoxymethane. Dimethyl methylphosphonate. Methylene bromide-Zinc-Titanium(IV) chloride. Methylenetriphenylphosphorane. N-Methylphenylsulfonimidoylmethyllithium. Titanium(O). N,N,P-Trimethyl-P-phenylphosphinothioic amide. Trimethylsilylmethyllithium. 

Magnesium, 12, 48 Malononitrile, 10, 66 Malonylurea, see Barbituric acid Mercuration, 12, 46, 54 Mercuric chloride, 12, 54 Mercuric oxide, 12, 44 Mercury di-/3-naphthyl, 12, 46 Mesaconic acid, 11, 74 Mcsitylene, 11, 24, 67 Methylamine, 12, 38 Methylamine hydrochloride, 10, 112 Methyl -amyI ketone, 10, 60 M ethylation of thiourea, 12, 52 Methyl benzoate, 10, 51 Methyl chloride, 10, 32, 36 Methylene bromide, 10, 112... 

In a 2-1. round-bottom flask placed on a steam bath and fitted with a stirrer, a separatory funnel, and a reflux condenser is placed 540 g. (1.9 moles) of commercial (88 per cent) bromo-form (Note 1). There is then added 10 cc. of a solution of sodium arsenite made by dissolving 230 g. (1.16 moles) of c. p. arsenious oxide and 445 g. (11 moles) of sodium hydroxide in 1.4 1. of water. The mixture is warmed gently to start the reaction, and then the remainder of the sodium arsenite solution is added during about one hour at such a rate that the solution refluxes gently. When the addition is complete, the flask is heated for four hours on the steam bath. The reaction mixture is distilled with steam, the lower layer of methylene bromide separated, and the water layer extracted once with 100 cc. of ether (Note 2). The methylene bromide is dried with 10 g. of calcium chloride and distilled. The yield of slightly yellow liquid boiling at 97-100° is 290-300 g. (88-90 per cent of the theoretical amount). 

RCHjCl — RCHJir. This conversion can be effected in good yield with NaBr in DMF at 100° in the presence of methylene bromide as a chloride ion scavenger. The transformation can also be effected with NaBr and C.H,Br in N-methyl-2-pyrrolidin()nc at 60-70°, but this reaction requires several days. 

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