Carbon tetrabromide → HCID 11035485, compound

HRID 1060255Notes

Reaction equation

HRID 1060255 reaction equation
[C:1]([Br:5])(Br)(Br)[Br:2].[CH:6]([O:9][C:10]1[CH:17]=[CH:16][C:13]([CH:14]=O)=[CH:12][C:11]=1[O:18][CH3:19])([CH3:8])[CH3:7]>C(Cl)Cl.[Zn]>[Br:2][C:1]([Br:5])=[CH:14][C:13]1[CH:16]=[CH:17][C:10]([O:9][CH:6]([CH3:8])[CH3:7])=[C:11]([O:18][CH3:19])[CH:12]=1

Participants

5

Reactant 2

HCID 11205Carbon tetrabromideHCID 7082534-isopropoxy-3-methoxybenzaldehyde

Product 1

HCID 11035485HCID 11035485, compoundYield 100.5%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

Carbon tetrabromide (51.3 g, 154.7 mmol) was added portion-wise to a magnetically stirred mixture of zinc dust (0.1 g, 154.5 mmol) and PP3 (40.5 g, 159.4 mmol) in CH2Cl2 (350 ml) maintained at 0° C. on an ice-salt bath. This suspension was allowed to warm to room temperature and then stirred at for a further 22 h. After this time the reaction mixture was re-cooled to 0° C. and vanillin isopropyl ether (15.0 g, 77.3 mmol) was added dropwise over 2 min. and allowed to stir at room temperature for 1 h. After dilution with hexane (200 ml) the resulting mixture was filtered through a sintered glass funnel and the filtrate concentrated on to silica gel (30 g). The resulting solid was added to the top of a flash chromatography column (silica gel: 20 cm long×10 cm wide) which was subjected to gradient elution (2:1, 1:1 and then 1:2 hexane/CH2Cl2). Concentration of the appropriate fractions (Rf 0.5 in 1:1 hexane/CH2Cl2) then afforded the title compound (27.2 g, 99.8%) as white crystalline masses, m.p. 36-38° C. IR(KBr disc, cm−1) 2976, 2973, 1599, 1510.1464, 1418, 1383, 1373, 1267, 1235, 1141, 1110, 1036. 1H NMR (300 MHz, CDCl3) δ7.41 (s, 1H), 7.21 (d, J=2.1 Hz, 1H), 7.07 (dd, J=2.1, 8.4 Hz, 1H), 6.87 (d, J=8.4 Hz), 4.58 (septet J=6.0 Hz, 1H), 3.87 (s, 3H), 1.39 (d, J=6.0 Hz, 6H). 13C NMR+APT (75.5 MHz, CDCl3) δ149.7 (C), 147.7 (C), 136.5 (CH), 127.9 (C), 121.9 (CH), 114.4 (CH), 111.8 (CH), 87.1 (CH), 71.1 (CH), 56.0 (CH3), 22.1 (CH3). MS (70 eV) m/z(%): 352 (28), 350 (49), 448 (31) (M+•), 310 (51), 308 (100), 306 (54) M+•−CH2CHCH3), 295 (34), 293 (38), 291 (36) (M+•−CH2CHCH3—CH). Anal. Calcd for C12H14O2Br2, 41.17; H. 4.03; Br, 45.65. Found: C, 41.21; H, 3.92; Br, 45.47.

Workup

  1. temperatureto warm to room temperature
  2. temperatureAfter this time the reaction mixture was re-cooled to 0° C.
  3. stirringto stir at room temperature for 1 h
  4. filtrationAfter dilution with hexane (200 ml) the resulting mixture was filtered through a sintered glass funnel
  5. concentrationthe filtrate concentrated on to silica gel (30 g)
  6. additionThe resulting solid was added to the top of a flash chromatography column (silica gel
  7. wash20 cm long×10 cm wide) which was subjected to gradient elution (2:1, 1:1

Sources & evidence

ORD record
ord-c08c2262a1544393b3249926cd6d171e
Source dataset
uspto-grants-2003_02
Patent number
US06521757B1

Reaction notes

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