Wall, Leo A. published the artcileReactions of polyfluorobenzenes with nucleophilic reagents, Safety of 4-Bromo-2,3,5,6-tetrafluorophenol, the publication is Journal of Research of the National Bureau of Standards, Section A: Physics and Chemistry (1963), 67A(5), 481-97, database is CAplus and MEDLINE.
A mixture of 26.5 g. C6F6, 26.5 g. 85% KOH, and 75 ml. H2O was heated in a sealed bomb at 175° for 5 hrs. with agitation to give 33.1 g. C6F5OH, b. 144-5°. A mixture of 67 g. C6F5H, 21.6 g. KOH, 150 ml. pyridine, and 2 ml. H2O was refluxed 1 hr., treated with 21.6 KOH, and refluxed 24 hrs. to give 21 g. 2,3,5,6-tetrafluorophenol, b20 47°. Similarly refluxing 36 g. C6F5Me and 28 g. KOH in 300 ml. tert-BuOH gave 12 g. 2,3,5,6-tetrafluoro-p-cresol, m. 52°. Reaction of 20 g. C6F5I with 2 g. KOH and 1 ml. H2O in 100 ml. pyridine gave only one product, 2,3,5,6-tetrafluoro-4-iodophenol, m. 79-81°; benzoate m. 59-60.2°. Reaction of 66 g. C6F5Br with 28.5 g. KOH and 1 ml. H2O in 150 ml. pyridine, however, gave a mixture of products: 3.5 g. 2-bromo-3,4,5,6-tetrafluorophenol, m. 41-3° (3,5-dinitrobenzoate, m. 104-5°); and 11.5 g. 4-bromo-2,3,5,6-tetrafluorophenol (3,5-dinitrobenzoate m. 131-3°). Similarly, 100 g. 2-chlorotetrafluoro-α,α,α-trifluorotoluene on treatment with 5.6 g. KOH and 1 ml. H2O in 100 ml. pyridine gave 2.5 g. 2-chlorotrifluoro-α,α,α-trifluoro-o-cresol, b15 92-3°, n24D 1.4510; and 15 g. 2-chlorotrifluoro-α,α,α-trifluoro-p-cresol, b15 102-3°, n24D 1.4510. The reactions of polyfluorobenzenes were then studied with alkoxides. A solution of 123.5 g. C6F5Br in 70 ml. pyridine was treated with a solution of 11.5 g. Na in 150 ml. MeOH during 1.5 hrs. and the mixture refluxed 15 hrs. and acidified with 1 l. 10% HCl to give 66 g. 4-bromo-2,3,5,6-tetrafluoroanisole, b5 79-81°, n25D 1.4812. Similarly, a mixture of 10 g. C6F5I in 50 ml. pyridine and 0.8 g. Na in 15 ml. MeOH on refluxing for 3 hrs. gave 1.5 g. unchanged C6F5I and 5.5 g. 2,3,5,6-tetrafluoro-4-iodoanisole (I), b20 113-15°, n22D 1.5229. Refluxing 1 g. I with 1 g. activated Cu powder for 12 min. gave 0.2 g. octafluoro-4,4′-dimethoxybiphenyl, m. 90-1.2°. To a cold solution of 9 g. Na in 250 ml. PhCH2OH was added 75 g. C6F6 and the mixture refluxed 24 hrs. to give 30 g. benzyl pentafluorophenyl ether (II), m. 44°. A better yield was obtained when a solution of 4.6 g. Na and 22 g. PhCH2OH in 250 ml. tert-BuOH was refluxed with 40 g. C6F6 for 40 hrs. to give 33 g. II. A solution of 8 g. C6F6 in 30 ml. HCONMe2 was treated with 5.28 g. PhOK and the mixture refluxed 0.5 hr. to give 1 g. 2,3,5,6-tetrafluoro-1,4-diphenoxybenzene, m. 147-9°, and 3.5 g. 2,3,4,5,6-pentafluorophenyl phenyl ether, (III), m. 29°. III was also obtained by heating a mixture of 11 g. C6F5OK, 15 g. PhBr, and 1 g. Cu at 210° in a sealed bomb. A solution of 6 g. C6F5OK and 12.8 g. C6F6 in 30 ml. HCONMe2 was refluxed 14 hrs. to give 1.5 g. bis(perfluorophenyl) ether, m. 67-9°, and a second product, m. 145-8°, probably p-bis(pentafluorophenoxy)2,3,5,6-tetrafluorobenzene. Similarly, a solution of 0.6 g. Na in 50 ml. EtOH refluxed with 5.3 g. C6F5NMe2 2 hrs. gave 5.1 g. 4-ethoxy-2,3,5,6-tetrafluoro-N,N-dimethylaniline, b. 34°. Reactions with amines were next investigated. A mixture of 280 g. C6F6 and 400 ml. 28% aqueous NH3 was rocked in a sealed bomb for 2 hrs. at 235° to give 236 g. C6F5NH2, m. 34°, and 28 g. tetrafluorophenylenediamine (sublimed 75°/1 mm.) shown by its nuclear magnetic resonance spectrum to be essentially the meta isomer mixed with a small amount of the para isomer. Similarly, heating a mixture of 56 g. C6F6 and 110 ml. 30% aqueous MeNH2 at 220° for 3 hrs. gave 59% C6F5NHMe, b. 170-2°, and 25% 2,3,5,6-tetrafluoro-N,N’-diphenylphenylenediamine, m. 94°. The reaction product obtained by heating 50 g. C6F6 and 110 ml. 25% aqueous Me2NH at 235° for 1 hr. was distilled at 1 mm. pressure and five fractions were collected. The first fraction (65%), b1 88°, was C6F5NMe2. Fraction 2, b1 88-126°, was shown by vapor phase chromatography to be C6F5NMe2 with 3 other compounds Fraction 3, b1 126-134°, consisted of 3 isomers of bis(dimethylamino)tetrafluorobenzene with the meta-isomer predominating. Fraction 4, b1 134-40°, contained equal amounts of the meta and para isomers. Fraction 5, b1 140-8°, was pure para isomer. The meta and para isomers could be separated by vapor phase chromatography. Similarly, heating a mixture of 30 g. C6F5Br and 70 ml. 28% NH4OH at 200° for 2 hrs. gave 22 g. p-bromotetrafluoroaniline, m. 61°. Heating 16 g. C6F5I and 30 ml. 8% NH4OH at 165° for 2 hrs. gave 7.6 g. tetrafluoro-p-iodoaniline, m. 77°. Benzyl pentafluorophenyl ether (20 g.) was heated with large excess of 28% NH4OH to give 3 g. p-(benzyloxy)tetrafluoroaniline, m. 97°. Similarly, heating 50 g. 2-chlorotetrafluoro-α,α,α-trifluorotoluene and 120 ml. 28% NH4OH at 21° for 2 hrs. gave 22 g. 2-chlorotrifluoro-α,α,α-trifluoro-p-toluidine, which decomposed readily at room temperature in the presence of air. To 100 ml. anhydrous NH3 at -70° were added 0.1 g. Fe(NO3)3 and 2.99 g. Na and, after disappearance of the blue color, 25 g. C6F5OMe during 45 min. After 5 hrs. at -70° the reaction mixture was worked up to give 7 g. unreacted C6F5OMe, 2.8 g. tetrafluoro-p-anisidine, m. 75-6.5°, 1.2 g. 4,4′-dimethoxyoctafluorodiphenylamine, m. 78-9°, and 2.2 g. 4,4′,4”-trimethoxydodecafluorotriphenylamine, b. 157-9°, n23D 1.5005. Diazotization of C6F5NH2 required concentrated acids since the salts of the amine hydrolyzed very readily in dilute solutions In 48% HBr, diazotization of C6F5NH2 gave C6F5N:NNHC6F5, probably owing to slow diazotization. The reaction was temperature-dependent, the diazoaminobenzene being formed much faster at 10° than at -10°. The product decomposed in warm HBr to give 5.4% C6F5Br and a mixture of o- and p-dibromotetrafluorobenzenes. In concentrated H2SO4 the reaction was very slow even at 25°. Addition of HOAc hastened it. Deamination with hypophosphorus acid gave a mixture probably of C6F5H and C6H2F4. Better diazotization could be carried out in liquid HF and the diazo product underwent successful Sandmeyer reaction. A solution of 20 g. C6F5NH2 in 75 ml. anhydrous HF at -20° was treated with 7.27 g. NaNO2 during 30 min. After stirring for 1 hr. at -10° the mixture was treated with 17.6 g. KI during 30 min. and allowed to warm to 25° in 1 hr. to give 16.5 g. C6F5I, b35 77-9°. Use of 12 g. KBr and 15 g. Cu2Br2 instead of KI gave 35% C6F5Br. The reaction of diazotized amine with C6F5OLi gave C6F5N:N(O)C6F5, which decomposed on removal of solvent. The Sandmeyer nitrile synthesis was not successful. A solution of 10 g. C6F5NH2 in 100 ml. HOAc was oxidized with 25 ml. 30% H2O2 at 25° for 24 hrs. to give decafluoroazoxybenzene (IV), m. 53-4°. A mixture of 5 g. IV, 15 g. Zn powder, 5 g. NH4Cl, 10 ml. H2O, and 75 ml. 95% EtOH refluxed 30 min. gave 2 g. decafluoroazobenzene, m. 57-9°. C6F6 reacted readily with organolithium compounds A solution of MeLi, prepared from 4.5 g. Li and 43 g. MeI in 50 ml. ether, was cooled to -10° to -20°, added dropwise to a solution of 60 g. C6F6 in 250 ml. pentane, and stirred for 17 hrs. at room temperature to give 34 g. C6F5Me, b. 115°. Similarly, reaction of BuLi, prepared from 1.86 g. Li and 18.3 g. BuBr in 30 ml. ether, with 25.3 g. C6F6 in 25 ml. ether gave 10.5 g. unreacted C6F6, 7 g. C6F5Bu, b25 86-7°, n20D 1.4229, and 2.5 g. of a compound, b1 230°, n20D 1.4683, probably impure tributyldifluorobenzene. Similarly, 32.7 g. C6F6 in 150 ml. ether with 0.18 mole PhLi in 250 ml. ether gave 8.5 g. 2,3,5,6-tetrafluoro-p-terphenyl, m. 220°, and 33 g. C6F5Ph, m. 69°. A similar reaction of 18.6 g. C6F6 and isopropenyllithium prepared from 12.1 g. 2-bromopropene gave 5 g. 2,3,4,5,6-pentafluoro-α-methylstyrene, b52 72-4°. With vinyllithium, prepared from 0.1 mole PhLi and 0.025 mole tetravinyltin, 18.6 g. C6F6 gave 4 g. unreacted C6F6 and 20% C6F5CH:CH2, b25 34°. LiAlH4 reduction of 21 g. C6F6 in ether gave 17 g. of a mixture of C6F6 and C6F5H which was separated by vapor phase chromatography to give 7.5 g. C6HF5. All the products in all above reactions were studied by infrared and nuclear magnetic resonance spectroscopy. The mechanism of reaction and the directional effects were discussed.
Journal of Research of the National Bureau of Standards, Section A: Physics and Chemistry published new progress about 1998-61-4. 1998-61-4 belongs to bromides-buliding-blocks, auxiliary class Fluoride,Bromide,Benzene,Phenol, name is 4-Bromo-2,3,5,6-tetrafluorophenol, and the molecular formula is C17H14O5, Safety of 4-Bromo-2,3,5,6-tetrafluorophenol.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary