5-BROMO-2-METHYL-2-PENTENE

105 kg of 12percent methyl magnesium bromide in THF corresponding to 12.6 kg of the same with 100percent concentration are charged into a stainless reactor.Keeping the reaction temperature between 30 and 35° C. by cooling with a brine bath 6.7 kg of cyclopropylmethylketone (II) are poured. Once pouring is complete, the reaction mixture is stirred at 30-35° C. for at least 1 hour, then cooled to 5-10° C. and the reaction mixture is poured into another enameled reactor containing 60 kg of 35percent sulphuric acid, cooled to 0-10° C.The reaction mixture is brought to a temperature between 25 and 30° C. and kept at that temperature for at least 15 minutes, then the phases are left to superate, the lower aqueous phase is removed.The organic phase is washed with 6.7 kg of demineralised water. It is stirred at 25-30° C. and left to decant to allow the separation of the two phases. The lower aqueous phase is removed.The solvent is removed from the organic phase by vacuum distillation until an oily residue is obtained, to which 10.1 kg of THF are added and the mixture is stirred until it is completely dissolved. Then the solution is poured into a container with suitable capacity and sent to the next stage.10 kg of product at 100percent are obtained.Yield: 77percent referring to the kg of cyclopropylmethylketone (II).105 kg of 12percent methyl magnesium bromide in THF corresponding to 12, 6 kg of the same with 100percent concentration are charged into a stainless reactor. Keeping the reaction temperature between 30 and 35°C by cooling with a brine bath 6.7 kg of cyclopropylmethylketone (II) are poured. Once pouring is complete, the reaction mixture is stirred at 30-35To a solution of methylmagnesium bromide (3M in Et2O, 60 mmol, 1.2 eq.) in THF (20 mL) was added dropwise a solution of cyclopropylmethyl ketone (4.21 g, 50 mmol, 1.0 eq.) in THF (7 mL). The mixture was then heated to reflux for 20 minutes. On cooling to room temperature, the reaction mixture was slowly added to a cooled solution of conc. sulphuric acid in water (1:2) at a rate that the temperature does not raise above 10°C. After addition, stirring was continued for 30 minutes. The organic layer was then separated and the aqueous phase extracted with Et2O. The combined organic extracts were washed with sat.NaHCO3 and brine, dried over Na2SO4, filtered and concentrated. The residue was distilled under vacuum (37 mmHg, 77°C) to give compound 10 as colorless oil (5.788 g, 71percent yield).To a solution of methylmagnesium bromide (3.0 M in Et2O, 31 mL, 97 mmol) in THF (30 mL) at 0 °C was added dropwise a solution of cyclopropyl methyl ketone (6.87 g, 80 mmol) in THF (12 mL). The mixture was heated under reflux for 20 min, cooled to room temperature then slowly added to a cooled solution of concentrated H2SO4 in water (60 mL, 1:2) at a steady rate so that the temperature did not rise above 10 °C. The resulting mixture was stirred for 30 min at 0 °C then the organic layer was separated. The aqueous phase was extracted with Et2O (3 × 50 mL) and the organic phases combined, washed with sat. NaHCO3 (100 mL) and brine (100 mL) and dried (MgSO4). The solvent was removed in vacuo to give the product as a yellow liquid (9.115 g, 55.89 mmol, 70percent).

Molecular Weight:163.06
XLogP3:2.9
Rotatable Bond Count:2
Exact Mass:162.00441
Monoisotopic Mass:162.00441
Heavy Atom Count:7
Complexity:60.6
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes