Tetrabromo-, methyl

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... 

Benzofurazan (benz-1,2,5-oxadiazole) reacted with bromine by addition to give a4,5,6,7-tetrabromo adduct. Bromine in hydrobromic acid solution 4-brominated both 5-methyl- and 5-bromo-benzofurazans (74JHC8I3). When 4,7-dinitrobenzofurazan was treated with ammonium chloride in refluxing acetic acid, nucleophilic displacement gave rise to the 4-chloro-7-nitro derivative (83URP1004375). Naphtho[l, 2-c]furazans (42) are mainly 4-halogenated, but there is minor substitution in the 8-position (73CHE1331). 

Dehydrochlorination with diethylaniline was explored for the preparation of 4//-thiopyran (7) and its 3-methyl and 4-isopropyl derivatives from 2,6-dichloro-l-thiacyclohexanes7,l9,24 303a (see Section III,B). Chlorosulfone 288b undergoes dehydrochlorination to 289.300 Chloro derivative 296 was similarly dehydrochlorinated with triethylamine to 4//-thiopyran sulfoxide (10).27 On the other hand, debromination of 2,3,5,6-tetrabromo derivative 297 with zinc surprisingly gives 2//-dioxide 9 instead of expected 10,46 probably due to an isomerization of 10 with ZnBr2. 

The crystal structure of 2,4,5,6-tetrabromo-l,3-dimethylbenzene (46) (Strel tsova and Struchkov, 1961b) is disordered in such a way that it is not possible to distinguish between bromine atoms and methyl groups in the molecule. The exocyclic atoms are displaced (0-018 A) alternately above and below the aromatic plane. Here again the level of significance is such that it is impossible to say whether or not intramolecular overcrowding is the cause of these deviations. 

Benzoin, IV, 87 Benzoquinone, oxime, IV, 101 —, phytochemical reduction of, IV, 89 o-Benzoquinone, tetrabromo-, IV, 89 p-Benzoquinone, tetrahydroxy-, III, 48 Benzoxazole, 5-acetamido-2-methyl-, III, 351... 

Aerothionin, a tetrabromo derivative, has been isolated from sponges Aplysina aerophoba and Verongia thiona the proposed structure is 24 (46). The oxime 25 was formed by treatment of aerothionin with dilute alkali. The relative positions of the aromatic substituents in 25 were established by cleavage in hot 6 N HC1 to give 26 and a lactone subsequently converted by methylation to 27. The tetramethyl derivative of 25 was hydrolyzed to form... 

Quite recently, this most sought after prize was won A group ofworkers succeeded in synthesizing a stable compound containing a -Si Si- triple bond. Sekiguchi and cowork-ers isolated l,l,4,4-tetrakis[bis(trimethylsilyl)methyl]-l,4-diisopropyl-2-tetrasilyne from reaction of 2,2,3,3-tetrabromo-1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]- 1,4-diisopropyl-tetrasilane with four equivalents of potassium graphite in tetrahydrofuran (equation 6). ... 

Tellurate(IV) [(3-Allyl-2-methyl-4,5-dihydro-1,3-oxazolium-5-yl)-methyl]-tetrabromo- El2b, 360 (TeCl4 + N,N-Dially 1-amide)... 

Beilstein Handbook Reference) BCG BRN 0372527 Bromcresol green EINECS 200-972-8 NSC 7817 Phenol, 4,4 - 1,1-dioxido-3H-2,1-benz-oxathiol-3-ylidene)bis(2,6-dibromo-3-methyl- Phenol, 4,4 -(3H-2,1-benzoxathiol-3-ylidene)bis(2,6-dibromo-3-methyl-, S,S-dioxide o-Toluenesulfonic acid, o-hydroxy-, gamma-sultone Tetrabromo-m-cresolphthalein sulibne. An acid indicator pH 3.8 (yellow)-5.4 (blue-green). Red-yellow crystals mp = 218.5° Xjn = 211, 278, 338,426 nm (e 54100. 8500, 7550, 17100 MeOH), 312, 394, 620 nm (s 13300, 8520, 40100 MeOH/KOH) insoluble in H2O, soluble in organic solvents. Lancaster Synthesis Co. Mallinckrodt Inc. Sigma-Aldrich Fine Chem. 

Tetrabromo derivative (240) treated with methyl lithium in benzene or LAH in THF undergoes a dehalogenation reaction leading to (274). When the reaction with methyl hthium is performed in ether, a mixture of pyrroles (275) and (276) is formed (Scheme 51) <75JOC47>. 

Bromoindole can be prepared by indirect bromination through A-(lithiocar-boxy)-2-lithioindole [51]. Subsequent 3-bromination followed by A-methylation gives 2,3-dibromo-l-methylindole in 92% yield. C-Ring bromination can then be carried out with one or two equivalents of bromine, giving the 2,3,6-tribromo and 2,3,5,6-tetrabromo derivatives [52]. 

---