Acetic acid, 2-(triphenylphosphoranylidene)-, methyl ester → HCID 58683729, compound

HRID 1991072Notes

Reaction equation

HRID 1991072 reaction equation
[Cl:1][C:2]1[C:9]([O:10][CH2:11][CH2:12][O:13][CH3:14])=[CH:8][C:5]([CH:6]=O)=[C:4]([N+:15]([O-:17])=[O:16])[CH:3]=1.[CH3:18][O:19][C:20]([CH:22]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)=[O:21]>C1(C)C=CC=CC=1>[CH3:18][O:19][C:20](=[O:21])/[CH:22]=[CH:6]/[C:5]1[CH:8]=[C:9]([O:10][CH2:11][CH2:12][O:13][CH3:14])[C:2]([Cl:1])=[CH:3][C:4]=1[N+:15]([O-:17])=[O:16]

Participants

4

Reactant 2

HCID 17453Acetic acid, 2-(triphenylphosphoranylidene)-, methyl esterHCID 85966687HCID 85966687, compound

Product 1

HCID 58683729HCID 58683729, compound

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

1-Chloro-2-(2-methoxyethoxy)-4-methyl-5-nitrobenzene (300 mg; 1.22 mmol) in DMF (3 ml) was treated with tert.butoxy-bis(dimethylamino)methan (1.06 ml; 5.1 mmol) in DMF (13 ml) at 160° C. for 20 min. The reaction mixture was evaporated to dryness and taken up in THF (6 ml). NalO4 (1.6 g; 7.3 mmol) in water (25 ml) was added at room temperature within 0.5 h and after stirring for another 1 h, the reaction mixture was extracted with EtOAc twice. The combined organic phases were dried over Na2SO4 and evaporated to dryness to yield the intermediate 4-chloro-5-(2-methoxyethoxy)-2-nitrobenzaldehyde as brown solid (360 mg; quant.). 4-chloro-5-(2-methoxyethoxy)-2-nitrobenzaldehyde (360 mg; 1.22 mmol) and (methoxycarbonylmethylen)triphenylphosphoran (449 mg; 1.34 mmol) were refluxed for 1 h in toluene (20 ml). After cooling the reaction mixture, toluene (100 ml) was added and the resulting crystals filtered off and purified via chromatography (SiO2, TBME/hexanes 1/1) to yield the title compound as a cis-trans mixture (290 mg). Recrystallisation from hot TBME rendered the pure trans isomer (180 mg; 47%) as slightly yellow crystals.

Workup

  1. additionwas added
  2. filtrationthe resulting crystals filtered off
  3. custompurified via chromatography (SiO2, TBME/hexanes 1/1)

Sources & evidence

ORD record
ord-bf397338406840d09a443d82f3c52ace
Source dataset
uspto-grants-2010_01
Patent number
US07645760B2

Reaction notes

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