Cuprous bromide chloride

Prepare a solution of p-tolyldiazonium chloride from 53 -5 g. of p-tolui-dine using the proportions and experimental conditions given under p-Chlorotoluene (Section IV,61). Add the diazonium chloride solution to the boiling cuprous bromide solution, and proceed as in Method 1. The yield of pure, colourless p-bromotoluene, b.p, 182-184° (mainly 183°), is 40 g. m.p. 26°,... 

Bromination of isoprene using Br2 at —5 ° C in chloroform yields only /n j -l,4-dibromo-2-methyl-2-butene (59). Dry hydrogen chloride reacts with one-third excess of isoprene at —15 ° C to form the 1,2-addition product, 2-chloro-2-methyl-3-butene (60). When an equimolar amount of HCl is used, the principal product is the 1,4-addition product, l-chloro-3-methyl-2-butene (61). The mechanism of addition is essentially all 1,2 with a subsequent isomerization step which is catalyzed by HCl and is responsible for the formation of the 1,4-product (60). The 3,4-product, 3-bromo-2-methyl-1-butene, is obtained by the reaction of isoprene with 50% HBr in the presence of cuprous bromide (59). Isoprene reacts with the reactive halogen of 3-chlorocyclopentene (62). 

By a procedure analogous to that described in the preceding experiment, octalone-2 (12 g, 0.08 mole, Chapter 9, Section III) in ether is added to methylmagnesium iodide in the presence of cuprous bromide (0.2 g). After decomposition with ice-acetic acid, extraction with ether, and washing of the ether extract, the ethereal solution is shaken with an equal volume (50-60 ml) of saturated aqueous sodium bisulfite for 3 hours. The mixture is filtered and the filtrate is reserved. The crystals are washed with ether. The filtrate is separated and the aqueous phase is combined with the filtered solid. The combination is acidified (dilute hydrochloric acid) and heated under reflux for 30 minutes. The product thus liberated is extracted into ether, the ether is washed with bicarbonate, then with saturated aqueous sodium chloride solution, and then dried and evaporated. The residual oil is the desired product, bp 250-254°. 

Kupfer-bromid, n. copper bromide, specif, cupric bromide, copper(II) bromide, -bro-mtir, n. cuprous bromide, copper(I) bromide, -chlorid, n. copper chloride, specif, cupric chloride, copper(II) chloride, -chloriir, n. cuprous chloride, copper(I) chloride, -cyamd, Ti. copper cyanide, specif, cupric cyanide, copper(II) cyanide, -cyaniir, n. cuprous cyanide, copper(I) cyanide, -dom, m. slag from liquated copper, -draht, m. copper wire, -drahtnetz, n. copper gauze, -drehspane,... 

Cuprous bromide, 44,12 Cuprous M-butylmercaptide, 42,22 Cuprous chloride as catalyst for 1,4 addition of Grignard reagents to <, (5-unsaturated esters, 41,63 Cyanoacetic acid, terl-butyl ester, 41,5... 

When a primary aromatic amine, dissolved or suspended in cold aqueous mineral acid, is treated with sodium nitrite, a dlazonlum salt is formed (Unit 13, Class XII). Mixing the solution of freshly prepared diazonium salt with cuprous chloride or cuprous bromide results in the replacement of the diazonium group by -Cl or -Br. 

Since sodium borohydride usually does not reduce the nitrile function it may be used for selective reductions of conjugated double bonds in oc,/l-un-saturated nitriles in fair to good yields [7069,1070]. In addition some special reagents were found effective for reducing carbon-carbon double bonds preferentially copper hydride prepared from cuprous bromide and sodium bis(2-methoxyethoxy)aluminum hydride [7766], magnesium in methanol [7767], zinc and zinc chloride in ethanol or isopropyl alcohol [7765], and triethylam-monium formate in dimethyl formamide [317]. Lithium aluminum hydride reduced 1-cyanocyclohexene at —15° to cyclohexanecarboxaldehyde and under normal conditions to aminomethylcyclohexane, both in 60% yields [777]. 

Cuprous bromide/dimethyl sulfide (54678-23-8), 66, 51 Cuprous chloride-pyridine complex, 66, 182 [2 + 2] CYCLOADDmON, 65, 135... 

Ammino-cuprous Bromides.—Cuprous bromide forms three definite compounds which correspond to the chlorides, namely, hexammino-cuprous bromide, [Cu2(NTI3)3Br2 triammino-cuprous bromide, [Cu2(NH3)3]Br3 and dianimino-cuproue bromide, [Cu2(NH3)2]Bra. 

The reactivity of each of the phenols in homopolymerization was determined by following the rate of oxygen absorption in a closed system. In each case, a plot of oxygen absorption against time was linear over at least 80 of the total reaction. Measurements were made at 25°C with a cuprous chloride-pyridine catalyst ai d at 60°C with a more active catalyst, cuprous bromide-tetramethylethylenediamine (TMEDA). Relative rates, from the slope of the linear portion of the oxygen absorption curves, are summarized in Table I. DMP is about 30 times more reactive than DDP at 25° C and five times more reactive at 60° C. MPP is intermediate in reactivity (as expected from its structure) at both temperatures but is comparable at the lower temperature with DMP and at 60°C with DPP (about a third slower than DMP at 25°C and 50 faster than DPP at 60°C). 

Oxidation of a mixture of equivalent weights of the two low-molecular-weight homopolymers at 25°C with a diethylamine-cuprous bromide catalyst yielded a copolymer that formed stable solutions in methylene chloride and could not be caused to crystallize by stirring with a 3 1 methanol/toluene mixture, a procedure that results in crystallization of DMP homopolymer or of the DMP portion of DMP-DPP block copolymers. The NMR spectrum was identical with that of the polymer obtained by simultaneous oxidation of the two monomers. 

Oxidation of Mixtures of Monomers. The method most likely to yield random copolymers of DMP and DPP is the simultaneous oxidation of a mixture of the two phenols, although this procedure may present problems because of the great difference in reactivity of the two phenols. The production of high molecular weight homopolymer from DPP is reported to require both a very active catalyst, such as tetramethylbutane-diamine-cuprous bromide, and high temperature, conditions which favor carbon-carbon coupling and diphenoquinone formation (Reaction 2) from DMP (II). With the less active pyridine-cuprous chloride catalyst at 25 °C the rate of reaction of DMP, as measured by the rate of oxygen... 

---