ChemicalBook CAS DataBase List 2,7-Dibromocarbazole

2,7-Dibromocarbazole synthesis

11synthesis methods

Product Name:2,7-Dibromocarbazole
CAS Number:136630-39-2
Molecular formula:C12H7Br2N
Molecular Weight:325

PHOSPHOROUS ACID TRIS(2-ETHYLHEXYL) ESTER

301-13-3

439797-69-0

136630-39-2

2,7-DibroMo-9-(2-ethylhexyl)-9H-carbazole

544436-46-6

Reaction of 4,4'-dibromo-2-nitro-1,1'-biphenyl (0.004 mol) and 4-nitrotoluene (0.006 mol) with an excess of tris(2-ethylhexyl) phosphite (0.05 mol) was carried out at 160 °C for 5 h (for the specific compounds j, k) or 17 h (for the specific compounds i, m), protected by argon gas. Upon completion of the reaction, the reaction was cooled to room temperature and the excess tris(2-ethylhexyl) phosphite and the resulting tris(2-ethylhexyl) phosphate were subsequently removed under vacuum. The reaction mixture was purified by silica gel column chromatography with the eluent of toluene/heptane (1:1, v/v) and the column size of 3 cm × 60 cm. The major product 2,7-dibromo-9-(2-ethylhexyl)-9H-carbazole (Rf = 0.8-0.9) was effectively separated from the by-product 2,7-dibromocarbazole (Rf = 0.5-0.6). The resulting compounds 7a-m were characterized by thin layer chromatography (TLC), elemental analysis, melting point determination, 1H NMR, 13C NMR and Fourier transform infrared spectroscopy (FTIR). Chromatographically purified compound 7 was used for melting point determination and further purified by methanol recrystallization. Non-alkylated carbazoles 8 (including 2,7-diiodocarbazole 10 (8a-c), 2,7-dibromocarbazole 8 (8d-f), 2,7-dichlorocarbazole 7 (8g-i), and commercial carbazole 11 (8j-m)) were obtained either by independent preparation or by commercial purchase and used for structural characterization.

439797-69-0
58 suppliers
$31.00/1g

136630-39-2
287 suppliers
$5.00/250mg

Yield:136630-39-2 82.5%

Reaction Conditions:

with triphenylphosphine in 1,2-dichloro-benzene at 180; for 3 h;

Steps:

6.3.6 2,7-Dibromo-9H-carbazole (11)

A solution of compound 10 (24.13g, 67.54mmol) and PPh₃ (44.27g, 168.88mmol) in o-dichlorobenzene (120mL) was stirred at 180°C for 3h. After cooled down to r.t., the reaction mixture was purified by column chromatography on silica gel using dichloromethane-hexane (1:5) as the eluent to give the final purified product as white-off solids with yield of 82.5% (18.09g). ¹H NMR (300MHz, (CD₃)₂SO) δ: 11.55 (s, 1H, -NH), 8.13-8.10 (d, J=8.4Hz, 2H, H₅), 7.75-7.74 (d, J=1.5Hz, 2H, H₂), 7.37-7.34 (dd, J₁=8.4Hz, J₂=1.8Hz, 2H, H₄); ¹³C NMR (75MHz, (CD₃)₂SO) δ: 141.74 (C₁), 123.05 (C₄), 122.89 (C₅), 121.95 (C₆), 119.66 (C₃), 114.81 (C₂); HRMS-EI (m/z): [M]⁺ calcd for C₁₂H₇Br₂N, 322.8945; found 322.8938 [(⁷⁹Br) (⁷⁹Br)M]⁺, 324.8950 [(⁷⁹Br) (⁸¹Br)M]⁺, 326.8954 [(⁸¹Br) (⁸¹Br)M]⁺.