Acetyl chloride → 2,4-Dibromo-5-hydroxyphenyl acetate

HRID 1481838Notes

Reaction equation

HRID 1481838 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([Br:8])[C:5]([OH:9])=[CH:4][C:3]=1[OH:10].C(N(CC)CC)C.[C:18](Cl)(=[O:20])[CH3:19]>ClCCl>[C:18]([O:9][C:5]1[CH:4]=[C:3]([OH:10])[C:2]([Br:1])=[CH:7][C:6]=1[Br:8])(=[O:20])[CH3:19]

Participants

5

Reactant 3

HCID 6367Acetyl chlorideHCID 8471TriethylamineHCID 2541394,6-Dibromobenzene-1,3-diol

Product 1

HCID 1178177972,4-Dibromo-5-hydroxyphenyl acetateYield 55%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

Under nitrogen, 4,6-dibromo-1,3-benzenediol (10.58 gram, 39.5 millimoles, 1.0 equivalent) and triethylamine (11.0 milliliter, 7.99 grams, 79.0 millimoles, 2.0 equivalents) dissolved in dichloromethane (80 milliliters) were cooled to 0° C. Acetyl chloride (3.09 milliliters, 43.4 millimoles, 1.1 equivalents) were added over the course of 17 minutes. The reaction was allowed to warm to room temperature and was stirred overnight. The reaction was worked up by removal of the volatiles by rotary evaporation. The solid residue was taken up in 100 milliliters ethyl acetate. The mixture was allowed to stir for 5 minutes, and the precipitate was removed by filtration. The product was purified by gradient flash column chromatography (ethyl acetate in hexane, 0 to 40%). The product was obtained in the form of a colorless solid (6.73 grams, 21.7 millimoles, 55%). m.p.: 121.3° C.; 1H-NMR (400 MHz, CDCl3) δ 7.69 (s, 1H), 6.85 (s, 1H), 5.59 (s, 1H), 2.34 (s, 3H); 13C NMR (101 MHz, THF) δ 168.12, 155.60, 149.52, 136.49, 112.77, 108.40, 106.30, 20.59; FTIR 570, 647, 690, 707, 768, 842, 872, 920, 1025, 1060, 1168, 1206, 1240, 1367, 1394, 1489, 1580, 1599, 1718, 2936, 2993, 3082, 3296 cm−1; UV/Vis: 221, 229 (overlapping), 292 nm; ESI/MS/MS of m/z=309: 309 [M79Br/81Br-H]−, 267 [M79Br/81Br—(CH2C═O, H)]−, 81 [81Br]−, 79 [79Br]−; HRMS (ESI−): calc. for C8H5Br2O3− [M-H]− 306.8605, found 306.8622.

Workup

  1. temperatureto warm to room temperature
  2. customThe reaction was worked up by removal of the volatiles by rotary evaporation
  3. stirringto stir for 5 minutes
  4. customthe precipitate was removed by filtration
  5. customThe product was purified by gradient flash column chromatography (ethyl acetate in hexane, 0 to 40%)

Sources & evidence

ORD record
ord-df445ce7c2794e3bbaf00834b70902e4
Source dataset
uspto-grants-2016_08
Patent number
US09410016B2

Reaction notes

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