Trimethyl borate → 7-Borono12,12-dimethyl-10-phenyl-10,12-dihydro-10-aza-indeno[2,1-b]fluorene

Participants

Reaction Conditions

Reaction Steps

22.3 g (51 mmol) of 7-bromo-12,12-dimethyl-10-phenyl-10,12-dihydro-10-azaindeno[2,1-b]fluorene 12 are dissolved in 600 ml of dry THF and cooled to −78° C. At this temperature, 26.2 ml (65.7 mmol/2.5 M in hexane) of n-BuLi are added over the course of about 5 min., and the mixture is subsequently stirred at −78° C. for a further 2.5 h. At this temperature, 7.3 ml (65.7 mmol) of trimethyl borate are added as rapidly as possible, and the reaction is allowed to come slowly to RT (about 18 h). The reaction solution is washed with water, and the precipitated solid and the organic phase are dried azeotropically with toluene. The crude product is washed by stir-ring with toluene/methylene chloride at about 40° C. and filtered off with suction, giving 16 g (82%) of the product as white solid.

Provenance & Evidence