1-Bromo-3-methyl-2-butanone

REFERENCE EXAMPLE 4 Step A; To a stirred solution of 3-methyl-2-butanone (27.0 g, 313 mmol) in methanol (150 mL) was added bromine (50 g, 313 mmol). The reaction was allowed to proceed (decolorization) below 1OIntermediate 13: [1-BROMO-3-METHYL-2-BUTANONE] To a solution [OF 3-METHYL-2-BUTANONE] (43g, [0.] [5MOL)] in dry methanol (300mL) at [0°C] was added [BR2] (80g, [0.] [5MOL)] slowly at the same temperature and then allowed to stir at [10°C] for lh. The reaction mixture became colourless, then quenched with water [(150ML)] and allowed to stir at rt for 20h. The reaction mixture was further diluted with water (450mL) and extracted with diethylether [(2X500ML).] The ether layer was washed with water, 10percent aqueous [K-, C03] solution, water, brine and dried with Na2SO4. The solvent was removed at rt to give 67g of [1-BROMO-3-METHYL-2-BUTANONE] as a liquid (75percent).Example 13-1: Process for preparation of α-bromo aldehydes and α-bromo ketones exemplified with the synthesis of l-bromo-3-methyl-butan-2-one (52).; EPO To a solution of 3-methyl-2-butanone (6.0 g; 69.7 mmol), dissolved in MeOH (40 mL), cooled to 0 °C, was added bromine (3.56 mL; 69.7 mmol), at a rate such that the internal temperature did not exceed 10°C. The reaction was allowed to stir for 45 min at 5-10°C, to which was then added HTo a solution of methyl isopropyl ketone (10.0 g, 114 mmol) in anhydrous methanol (110 mL) cooled to -30° C. under a nitrogen atmosphere was added bromine (5.8 mL, 114 mmol) dropwise and the reaction was allowed to warm to room temperature and stirred for 3 h. The reaction was concentrated in vacuo diluted with diethyl ether and washed with aqueous saturated NaHCOTo an ice cooled solution of 3-methyl-2-butanone (25.8 g, 300 mmol) in EtOH (250 ml) was added drop wise bromine (12.9 ml, 250 mmol) and the mixture was stirred for two hours in an ice bath. Step 1: Preparation of l-bromo-3-methylbutan-2-one 68. To a solution of 3- methyl-2-butanone (40.7 g, 1 eq.) in ethanol (391 mL) was added bromide (62.4 g, 0.83 eq.) under nitrogen at OTo a solution of 3- methyl-2-butanone (40.7 g, 1 eq.) in ethanol (391 mL) was added bromide (62.4 g, 0.83 eq.) under nitrogen at 0To a solution of 3-methyl-2-butanone (40.7 g, 1 eq.) in ethanol (391 mL) was added bromide (62.4 g, 0.83 eq.) under nitrogen at 0° C. over 30 min. Preparation of 1-Bromo-3-methyl-but-2-one A solution of 1 g (1 1.61 mmol) of 3-methylbutan-2-one in 6 mL of methanol is cooled to a temperature of 10°C. When the temperature is reached, 597 μl (1 1.61 mmol) of bromine are added. The reaction mixture is stirred at 10°C until fully decolorized, and stirring is then continued for 30 minutes at room temperature. After adding 10 mL of water to the solution, stirring is continued for 1 hour at room temperature. The reaction mixture is then taken up in water and extracted with ethyl ether. The organic phase is washed with aqueous 10percent NaA solution of 1 g (11.61 mmol) of 3-methylbutan-2-one in 6 mL of methanol is cooled to a temperature of 10° C.

Molecular Weight:165.03
XLogP3:1.8
Hydrogen Bond Acceptor Count:1
Rotatable Bond Count:2
Exact Mass:163.98368
Monoisotopic Mass:163.98368
Topological Polar Surface Area:17.1
Heavy Atom Count:7
Complexity:68.5
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes