Hydrochloric Acid → 1-Bromo-4-cyclopropoxybenzene

With reference to the document (Tetrahedron Lett., (1998), 39, 8621-8624), the following cyclopropanization was conducted. Diethyl zinc (1.0 M hexane solution, 250 mL, 250 mmol) was added to dichloromethane (250 mL), and a solution of dichloromethane (120 mL) containing trifluoroacetic acid (19.2 mL, 249 mmol) was added thereto under ice-cooling over 100 minutes. The mixture was further stirred for 1 hour. Then, a solution of dichloromethane (100 mL) containing chloroiodomethane (20.1 mL, 250 mmol) was added thereto under ice-cooling over 40 minutes, and a solution of dichloromethane (120 mL) containing 1-bromo-4-(vinyloxy)benzene (32.8 g, 165 mmol) prepared in Example 6 (6b) was further added thereto at the same temperature over 20 minutes. The mixture was stirred at room temperature for 1.5 hours. Then, 0.1 N hydrochloric acid (400 mL) was added to the reaction solution. The mixture was stirred for 30 minutes, filtered through Celite, and washed with hexane (200 mL). The filtrate and the hexane washing solution were combined. The organic layer was washed with 0.1N hydrochloric acid (100 mL) and then with saturated brine (100 mL) containing about 1 g of sodium sulfite twice. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was evaporated to give 36.0 g of 1-bromo-4-(cyclopropyloxy)benzene (yellow oil).

1. additionwas added
2. temperatureunder ice-cooling over 100 minutes
3. additionwas added
4. temperatureunder ice-cooling over 40 minutes
5. additionwas further added
6. waitat the same temperature over 20 minutes
7. stirringThe mixture was stirred at room temperature for 1.5 hours
8. stirringThe mixture was stirred for 30 minutes
9. filtrationfiltered through Celite
10. washwashed with hexane (200 mL)
11. washThe organic layer was washed with 0.1N hydrochloric acid (100 mL)
12. additionwith saturated brine (100 mL) containing about 1 g of sodium sulfite twice
13. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
14. customthe solvent was evaporated

ORD record

ord-1a7c76b4d5ae4840a335d20229645f4f

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08143446B2