5.5.10.10- tetrabromo

Bromcresol green, tetrabromo-m-cresol-sulfonphthalein (indicator) dissolve 0.1 g in 7.15 mL 0.02 N NaOH and dilute with water to 250 mL or, 0.1 g in 100 mL 20% alcohol pH range yellow 4.0-5.6 blue. 

The Brominated Flame Retardants Industry Panel (BFRIP) was formed ia 1985 within the Flame Retardant Chemicals Association (FRCA) to address such concerns about the use of decabromodiphenyl oxide. Siace 1990 the BFRIP has operated as a Chemical Self-Funded Technical Advocacy and Research (CHEMSTAR) panel within the Chemical Manufacturers Association (CMA) (64). As of 1993, members of BFRIP are Ak2o, Amerihaas (Dead Sea Bromine Group), Ethyl Corp., and Great Lakes Chemical. Siace its formation, BFRIP has presented updates to iadustry on a regular basis (65,66), and has pubhshed a summary of the available toxicity information on four of the largest volume brominated flame retardants (67,68) tetrabromo bisphenol A, pentabromodiphenyl oxide, octabromodiphenyl oxide, and decabromodiphenyl oxide. This information supplements that summarized ia Table 11. 

The stmcture of indophenol-type sulfur dyes was studied (21) on Cl Sulfur Blue 9 made from the indophenol (13). This compound was purified and brominated to a tetrabromo derivative (14) identical with that obtained on hromin ation of Methylene Violet [2516-05-4] (15). 

Tribromophenol can be further brominated in buffered acetic acid to give 2,4,4,6-tetrabromo-2,5-cyclohexadien-l-one [20244-61-5] a useful hrominating agent (26). 

A great variety of differently substituted pteridine derivatives have been synthesized starting from (109) or the 2,4,6,7-tetrabromo compound (60USP2940972), which shows a corresponding reactivity pattern. Amines at low temperature substitute only the 6- and... 

Pteridine, 6-oxo-5,6,7,8-tetrahydro-electrochemistry, 3, 285 Pteridine, 7-oxo-5,6,7,8-tetrahydro-electrochemistry, 3, 285 Pteridine, 2-phenyl-structure, 3, 266 Pteridine, 4-phenyl-structure, 3, 266 Pteridine, 7-phenyl-oxidation, 3, 305 Pteridine, 2,4,6,7-tetraamino-synthesis, 3, 291 Pteridine, 2,4,6,7-tetrabromo-reactions, 3, 291 Pteridine, 2,4,6,7-tetrachloro-hydrolysis, 3, 291 properties, 3, 267 Pteridine, 1,2,3,4-tetrahydro-structure, 3, 280 Pteridine, 5,6,7,8-tetrahydro-reduction, 3, 280 synthesis, 3, 305 Pteridine, 2,4,6,7-tetramethyl-NMR, 3, 266... 

Bromocresol Green (3, 3",5, 5"-tetrabromo-m-cresolsulfonephthalein) [76-60-8] M 698.0, m 218-219 (dec), 225 (dec), pK 4.51. Crystd from glacial acetic acid or dissolved in aqueous 5% NaHC03 soln and ppted from hot soln by dropwise addition of aqueous HCl. Repeated until the extinction did not increase (X ,ax 423nm). Indicator at pH 3.81 (yellow) and pH 5.4 (blue-green). 

PENTAERYTHRITYL BROMIDE AND IODIDE (sj m.-Tetrabromo- and Tetraiodo-neo-pentane)... 

In practice the bromo analogue has been more widely used. This arises from a combination of two reasons. In the first instance the tetrabromo resin contains 48% halogen whilst the tetrachloro resin contains 30% halogen. 

Testosterone acetate, 312, 320, 322, 343 lOa-Testosterone acetate, 320 5a,6/3,17a,21-Tetrabromo-3/3-hydroxy-pregnan-20-one acetate, 160 3,ll/3,17a,21 -tetrahy droxy- 19-norpregna-l,3,5(10)-trien-20-one 11,21-diacetate 3-methyl ether, 224... 

An extensive study of the amination of halopyridines has been carried out by den Hertog and co-workers.A comparison of their results with studies in inert solvents using primary and tertiary amines should permit some evaluation of the postulated factors. 2,4-Dichloropyridine in concentrated aqueous ammonia (180°, 5 hr) resulted in the formation of 4-amino- (60% yield) and 2-amino-chloropyridines (20% yield). Under similar conditions, only 4-substitution of 3,4,6-trichloro- and of 2,3,4,5-tetrabromo- and -tetrachloro-pyridines was observed. However, in these and the other polyhalo pyridines, the appreciable and unequal mutual activation by the halogen substituents needs to be emphasized. 

The inferior activation in the 3- or 6eto-position is illustrated by the very large difference in reactivity in the following aminations and alkoxylations. In the reaction of 2-chloro-5-iodopyridine or 2,3-dibromopyridine (cf. 295) with boiling methanolic methoxide, only the 2-halogen is displaced as is also the case in the amination of 2-chloro-3,5-diiodopyridine and of 2,3,6-tribromopyridine. 4-Amination of 3,4-dibromo-, 2,3,4,5-tetrabromo-, and 3-bromo-4-chloro-pyridine occurred. Only 2-amination (aqueous NH3, 190°, 36 hr) occurred with 2,3-dichloropyridine (295) and only 4-ethoxyla-tion (alcoholic ethoxide, 160°, 4 hr) with 3,4-dichloropyridine. ... 

Bromocresol green Tetrabromo-m-cresolsulphonphthalein 3.6-5.2 Yellow Blue 4.7... 

Another application of this method is the synthesis of 5,10-epoxy[10]annulene (7) from 2,3.6,7-tetrabromo-4a,8a-epoxydecahydronaphthalene.152-154 The byproduct is 1-benzoxepin (8). The 5,10-cpoxyannulcnc (7) incorporates the oxepin structure. The annulene can be converted to 1-benzoxepin by proton catalysis.153154... 

The 5,10-epoxy[10]annulene system readily undergoes addition of bromine with formation of an epoxide across the central bond. By dehydrohalogenation the annulene structure can be restored. For example, the dibromo and tetrabromo adducts of 5,10-epoxy[10]annulene can be converted with potassium rm-butoxide to l-bromo-5,10-epoxy[10]annulene (13) and 1,6-dibromo-5,10-epoxy[10]annulene (14), respectively.159... 

Tetrapropylporphycene 6 is brominated on treatment with bromine in a two-phase system of carbon tetrachloride and water at the four /(-pyrrolic positions26 to yield the tetrabromo derivative 7. 

The tetrabromo porphycene was used as a starting product for the first synthesis of isocorroles (see Section 1.8.) which are formed from the porphycene by ring contraction on treatment with base. 

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