N-bromobutanimide → methyl 7-(bromomethyl)-9-oxo-9H-xanthene-1-carboxylate

HRID 1091457Notes

Reaction equation

HRID 1091457 reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:18]2[C:17](=[O:19])[C:16]3[C:11](=[CH:12][CH:13]=[C:14]([CH3:20])[CH:15]=3)[O:10][C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4].[Br:21]N1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[CH3:1][O:2][C:3]([C:5]1[C:18]2[C:17](=[O:19])[C:16]3[C:11](=[CH:12][CH:13]=[C:14]([CH2:20][Br:21])[CH:15]=3)[O:10][C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4]

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 21304614Methyl 7-methyl-9-oxo-9H-xanthene-1-carboxylate

Product 1

HCID 21304612methyl 7-(bromomethyl)-9-oxo-9H-xanthene-1-carboxylateYield 45%

Reagents, catalysts & solvents 2

HCID 7187Benzoyl PeroxideCatalystHCID 5943Carbon TetrachlorideSolvent

Procedure

Brominating agents include N-bromosuccinimide, bromine, complexed bromine such as pyridinium bromide, and the like can be used to convert 7-methyl-9-oxoxanthene-1-carboxylic acid methyl ester 40 to 7-bromomethyl-9-oxoxanthene-1-carboxylic acid methyl ester 41. Solvents include chlorinated hydrocarbons, dipolar aprotic solvents, and various ethers. Temperature can range from 0-100 C. For example, a suspension of 7-methyl-9-oxoxanthene-1-carboxylic acid methyl ester (0.1 mol), N-bromosuccinimide (0.12 Mol) and benzoylperoxide (10 mg) in dry carbon tetrachloride (300 mL) is stirred at 60 C for 6 hours. The mixture is filtered, and the solid is washed successively with small amounts of chloroform, water and ether, and then dried to leave a desired product as white solid. For example, to a solution of compound 40 (1.97 g, 7.4 mmol) in carbon tetrachloride (400 mL) was added N-bromosuccinimide (1.44 g, 8.1 mmol) and a catalytic amount of benzoyl peroxide (45 mg, 3%). The reaction mixture was heated to reflux for 6 h and cooled to room temperature. The white precipitate was filtered out. The solvents were removed and the residue was recrystallized from EtOAc and hexanes. The crude product (2.05 g) was obtained and further recrystallization gave a pure white solid product 41 (1.15 g, 45%). 1H NMR (400 MHz, CDCl3) of 2: 8.27 (d, J=2.5 Hz, 1H), 7.80-7.72 (m, 2H), 7.57 (dd, J=8.5 and 1.1 Hz, 1H), 7.48 (d, J=8.5 Hz, 1H), 7.33 (dd, J=7.0 and 1.1 Hz, 1H), 4.57 (s, 2H), 4.00 (s, 3H).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 6 h
  3. filtrationThe white precipitate was filtered out
  4. customThe solvents were removed
  5. customthe residue was recrystallized from EtOAc and hexanes
  6. customThe crude product (2.05 g) was obtained
  7. customfurther recrystallization

Sources & evidence

ORD record
ord-44254813c07647f7a0c761598f00e29d
Source dataset
uspto-grants-2012_03
Patent number
US08129382B2

Reaction notes

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