General Method G: Cyclopropanation Reaction (0459)
Ethylmagnesium bromide (3.0 M ethyl ether solution, 1.1 eq.) was added slowly and dropwise to a stirred mixture of arylonitrile (1 eq.) and tetraisopropoxytitanium (1.7 eq.) at -70 °C. The reaction mixture was gradually warmed to 25 °C and stirred continuously for 1 hour. Subsequently, boron trifluoride ethyl ether complex (3 eq.) was added dropwise to the reaction system at 25 °C. After the dropwise addition was completed, stirring of the reaction mixture was continued for 2 hours. After completion of the reaction, the reaction was quenched with 2M aqueous hydrochloric acid. Next, the pH of the reaction solution was adjusted to alkaline with 2M aqueous sodium hydroxide solution. The organic material in the reaction solution was extracted with ether. The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated. The crude product was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate, ratio from 10:1 to 1:1 gradient elution) to obtain the target product 1-arylcyclopropylamine.
Example 64: Synthesis of quinuclidinyl cyclic-3-yl 1-(biphenyl-4-yl)cyclopropyl carbamate
4-Bromobenzonitrile (3.00 g, 16.5 mmol) was converted to 1-(4-bromophenyl)cyclopropylamine (1.80 g, 51% yield) according to General Method G. The product was a yellow solid.
