2-chloro-10,10-dibromo-8-methyl

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). 

This study was designed to evaluate the performance of commonly used biocides against the performance of a new liquid blend. In order to choose an effective preservative package, the two main criteria the biocide must have, are (i) to be approved by the US Food and Drug Administration (FDA) under sections 21 CFR 176.170 and 21 CFR 176.180 which cover components of paper and paperboard in contact with foods and (ii) to be designated as a safe biocide (low toxicity, non-sensitiser, easy to handle). The three most commonly used products (i) 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one, (ii) 1,5-pentanedial and (iii) l,2-benzisothiazolin-3-one, currently meet the above criteria. The new liquid blend, l,2-dibromo-2,4-dicyanobutane -I- 2-bro-mo-2-nitropropane-l,3-diol was also designed to meet the criteria. 

Bromination of (VI) gives the dibromo derivative which, on refluxing in methanol, followed by dehydrobromination with KOH in refluxing methanol, gave lo-methoxy-4H-benzo- [ 4,5] -cyclohepta- [l,2-b] --thiophene-4-one (IX). This compound was condensed with the magnesium derivative of 4-chloro-l-methyl-piperidine in tetrahydrofurane, and the resulting lo-methoxy-4-(l-methyl-4-piperidyl)-4H-benzo[4,5]--cyclohepta-[1,2-b]-th phene-4-one (X) was finally dehydrated and demethylated with HC1 at 95-loo°C, to give the base of ketotifen (4). 

Bis-[chloromcthyl]-2, 2 -dichloro- 646 2-Bis-[4-methoxy-phenyl]- 1699 2-Bis-[4-methyl-phenyl]- 1699 l -Bis-[trimethylsilyl]- 1691 (Bis-[triphenylphosphan]-chloro-nickelo)-2,2,2, 2 -tetramethyl- 225 3 (or 3,3 )-Bis-[trimethylsilyl]-2,2 -dichloro- 2710 Bromo- 1443 Bromo-l-methoxy- 1508 Bromo-1-methoxy- 1508 Bromo-1-methyl- 1271 Bromo-1-methyl- 1271, 2699 Chloro- 946 Chloro-l-cyano- 558 Chloro-1, 2-dimethyl- 550 Chloro-2,2(or 2,3)-dimethyl- 558, 559 Chloro-3-ethyl-2-methyl- 558 Chloro-l-methyl- 2699 Chloro-2-methyl- 551 Chloro-2,2,2 -trimethyl- 558 Chloro-2,2,3,3-tetramethyl- 558, 559 ( 1 -Cyclopentenyl)-1 -methoxy- 1889 2 -Dibromo-2,2-dichloro-l-methyl- 2194, 2 -Dibromo-l,r-dimethyl- 2700 (2,2-Dibromo-cthcnyl)-2-phcnyl- 1792, 2-Dibromo-l-methyl- 1271 (Dibromomethylen)-l-methyl- 2302, 2-Dibromo-l-methyl-3-methylen- 2302, 2 -Di-tcrt.-butyl-2,2 -dimethyl-3,3.3, 3 -tetra-bromo- 2413... 

A rational process involving a copper catalyst in a flow tube at 360° has been worked out for the preparation of dibromo(methyl)phosphine and (bromo)dimethylphosphine and the corresponding chloro compounds ethyl halides give only poor yields by this technique, and butyl bromide does not react at all.177,178 Dichloro(trichloromethyl)phosphine has also been obtained on y-irradiation of white phosphorus in carbon tetrachloride, yields being up to 41% at 130°.179... 

Account for the fact that 2-methyl-l,3-butadiene reacts (a) with HCl to yield only 3-chloro-3-methyl-l-butene and l-chloro-3-methyl-2-butene (b) with bromine to yield only 3,4-dibromo-3-methyl-l-butene and 1,4-dibromo-2-methyl-2-butene. 

Chloro-2-methyl-4-isothiazolin-3-one and 3-methyl-4-isothiazolin-3-one 1,3-Dibromo-5,5-dimethylhydantoin Dodecylguanidine hydrochloride... 

Chem. Descrip. Disp. of 1,2-dibromo-2,4-dicyanobutane, 5-chloro-2-methyl-4-isothiazolin-3-one, and 2-methyl-4-isothiazolin-3-one... 

N-Alkylpyridones are demethylated when undergoing substitutions of this kind or are converted to pyridinium salts. For example, A-benzyl-3,5-dibromo-4-py idone (MI-620) and phosphorus pentachloride in toluene form 3,S-dibromo-4-chloropyridine and a small amount of N-benzyl-3,5-dibromo-4-chloropyridinium chloride. A -Methyl-5-nitro-2-pyridone and thionyl chloride in dimethylformamide give 2-chloro-l-methyl-5-nitropyridinium chloride. ... 

Retention-aid chemicals may be added, as well as defoamers (e.g. fatty-acid compounds), pitch-control agents, optical brighteners (usually stilbene derivatives) and, in some cases, fibre deflocculants. Different slimicides are also added to the stock for microbe control. A number of chemicals can be used for this purpose, such as 1,5-pentanediol, 2,2-dibromo-3-nit-rile propionamide, 2,2-dibromo-2-cyanoacetamide, 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-iso-thiazolin-3-one (Kathon CG) or glutaraldehyde. 

In the s3mthesis of riboflavin and some related flavins, better yields are often available through the use of 5-chloro- or 5,5-dichlorobarbituric acid place of alloxan. In addition to riboflavin, 6-methyl-9-2 i, y-methyl-g- s, 6-ethyl-9-3 , 7-ethyl-9-2 , 6,7-diethyl-9- , 6-ethyl-7-methyl-9-2 .3 , 5,7-di-niethyl-9- , 6,8-dimethyl-9- , 6,7-dichloro-9-29.72 6-chloro-9-3 -, 6-flu-oro-9-3 , 6,7-dibromo-9- , 5,6-dimethyl-9- , 6-chloro-7-methyl-9-2 , 6-meth-yl-7-chloro-9-, 3,6,7-trimethyl-9-(i -D-ribityl)isoalloxazine2 (using 2-methylalloxan), and 6,7-dichloro-9-(i -D-sorbityl)isoalloxazine i have been prepared by this method. 

Reaction of MeaSiHCNa with dichloro and dibromo complexes in GHaCla/acetone/HaO causes formal insertion of CH2 groups into the Pt-Cl and Pt-Br bonds, and affords complexes with halomethyl ligands 61-63. The reaction of diazomethane forms a bis(chloromethyl)platinum complex 64, while ethyl diazoacetato undergoes insertion into one of the Pt-Cl bonds to yield the complex having a chloro(ethoxycarbonyl)methyl ligand 65 (Scheme 7). ... 

Methyl and Ethyl, 504 9-Fluorenylmethyl, 506 9-(2-Sulfo)fluorenylmethyl, 507 9-(2,7-Dibromo)fluorenylmethyl, 507 17-Tetrabenzo[a,c,gf,/]fluorenylmethyl, 508 2-Chloro-3-indenylmethyl, 508 Benz[f]inden-3-ylmethyl, 508... 

Bromomethyl-3,4-dibromo-3,4-dihydrocoumarin 1 (Fig. 11.4) and its chloro-methylated analogue 2b rapidly and progressively inactivate a-chymotrypsin and also the activities of a series of trypsin-like proteases. A benzyl substituent characteristic of good substrates of a-chymotrypsin was introduced at the 3-position to make inhibition more selective. This substituted dihydrocoumarin 3 irreversibly inhibited a-chymotrypsin and other proteases. These functionalized six-membered aromatic lactones, and their five- and seven-membered counterparts, 3//-benzofuran-2-ones 2a26 and 4,5-dihydro-3//-benzo[b]oxepin-2-ones 2c,27 were the first efficient suicide inhibitors of serine proteases. Their postulated mechanism of action is shown in Scheme 11.2. 

Potassium 4-chloro-3,5-dinitrobenzene-sulfonate, 31, 46 Potassium cyanate, 31, 9 Potassium cyanide, 30,84 32,31,63 37,47 Potassium ethyl malonate, 37, 34 Potassium ethyl xanthate, 30, 56 Potassium fluoride, 36, 40 Potassium iodide, 30, 34 31, 31, 66 Potassium metal, 37, 29, 30 Potassium methyl sulfate, 31, 73 Potassium nitrate, 31, 46 Potassium 1-nitropropylnitronate, 37, 24 Potassium oxalate, 34, 83 Potassium permanganate, 30, 87 31, 59 Potassium sulfide, 32, 103 Potassium thiobenzoate, 32, 101 Potassium thiocyanate, 32, 39, 40 Prins reaction, 33, 72 Propane, 1, 3-dibromo-2, 2-Ws-(bromo-methyl)-, 31, 82... 

Azatricyclo[2.2.1.02 6]hept-7-yl perchlorate, 2368 f Azetidine, 1255 Benzvalene, 2289 Bicyclo[2.1.0]pent-2-ene, 1856 2-/ert-Butyl-3-phenyloxaziridine, 3406 3 -Chloro-1,3 -diphenyleyclopropene, 3679 l-Chloro-2,3-di(2-thienyl)cyclopropenium perchlorate, 3388 Cyanocyclopropane, 1463 f Cyclopropane, 1197 f Cyclopropyl methyl ether, 1608 2,3 5,6-Dibenzobicyclo[3.3.0]hexane, 3633 3,5 -Dibromo-7-bromomethy lene-7,7a-dihy dro-1,1 -dimethyl-1H-azirino[l,2-a]indole, 3474 2.2 -Di-tert-butyl-3.3 -bioxaziridinc, 3359 Dicyclopropyldiazomethane, 2824 l,4-Dihydrodicyclopropa[ >, g]naphthalene, 3452 iV-Dimethylethyl-3,3-dinitroazetidine, 2848 Dinitrogen pentaoxide, Strained ring heterocycles, 4748 f 1,2-Epoxybutane, 1609 f Ethyl cyclopropanecarboxylate, 2437 2,2 -(l,2-Ethylenebis)3-phenyloxaziridine, 3707 f Methylcyclopropane, 1581 f Methyl cyclopropanecarboxylate, 1917 f Oxetane, 1222... 

Bromo substituents in the 6- and 6 -positions of 2,2 -bipyridines are particularly reactive, being readily converted to amino,cyano, ° al-koxyl, hydrazino, chloro, and hydrogen groups and by way of the corresponding lithio derivatives to carboxyl, methyl, aldehyde or alkylcarbonyl, and other groupings. 6,6 -Dibromo-2,2 -bi-pyridine also reacts with the disodium derivatives of polyethylene glycols to give crown ethers akin to 100, and 6,6 -bis(chloromethyl)-2,2 -bi-pyridine " and the derived 6,6 -bis(mercaptomethyl)-2,2 -bipyridine... 

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