1,2-DIBROMO-3,4-DIFLUOROBENZENE synthesis

Yield:173276-99-8 70%

Reaction Conditions:

with n-butyllithium in diethyl ether;ethyl acetate;

Steps:

3 Compounds Formed by Reactions Involving Alcohols

6,7-Difluoro-1,4-epoxy-1,4-dihydronaphthalene (24). To 3,4-difluoro-1,2-dibromo-benzene (0.75 g, 2.78 mmol) and furan (1 mL, 14.7 mmol) in Et₂O (15 mL) at -78° C. was added BuLi (1.1 mL, 2.5M in hexanes, 2.75 mmol) dropwise. The reaction was stirred for two hours at -78° C. and then was allowed to warm to room temperature. After 2 hours, the reaction mixture was quenched with water dropwise and then was poured into water. The organic layer was separated and the aqueous layer was extracted three times with Et₂O. The combined organic layers were washed with brine, dried over MgSO₄, concentrated and chromatographed (25% ethyl acetate:hexanes) on silica gel to give 24 (350 mg, 70%) as a colourless oil. R_f=0.21 on silica gel (20% ethyl acetate:hexanes); bp 40° C. ? 0.5 mmHg]; IR (neat, cm^-1), 3017 (M), 1624 (s), 1465 (s), 1365 (s), 1253 (s), 1190 (m), 1040 (s), 857 (s). ¹H NMR (400 MHz, CDCl₃) δ7.06 (2H, dd, J^H-F=7.7, 7.7 Hz), 7.01 (2H, s), 5.67 (2H, s); ¹³C NMR (400 MHz, CDCl₃) δ147.2 (dd, J^C-F=247.9, 14.5 Hz), 145.1 (dd, J^C-F=4.3, 4.3 Hz), 143.1, 110.8 (m), 82.1. HRMS calcd for C₁₀H₆O (M⁺): 180.0387. Found: 180.0394.

References:

US6525068,2003,B1