Sodium hydride → 3-Methoxy-7-(4-methoxyphenyl)hepta-2,4,6-trienoic acid

HRID 1109438Notes

Reaction equation

HRID 1109438 reaction equation
[H-].[Na+].[CH3:3][O:4][C:5]1[CH:14]=[CH:13][C:8]([CH:9]=[CH:10][CH:11]=O)=[CH:7][CH:6]=1.[CH3:15][O:16]/[C:17](/[CH3:23])=[CH:18]\[C:19]([O:21]C)=[O:20]>O1CCCC1>[CH3:15][O:16][C:17]([CH:23]=[CH:11][CH:10]=[CH:9][C:8]1[CH:13]=[CH:14][C:5]([O:4][CH3:3])=[CH:6][CH:7]=1)=[CH:18][C:19]([OH:21])=[O:20]

Participants

5

Reactant 3

HCID 24758Sodium hydride2×HCID 2309953-(4-Methoxyphenyl)prop-2-enalHCID 1223348935217-21-1

Product 1

HCID 541068463-Methoxy-7-(4-methoxyphenyl)hepta-2,4,6-trienoic acidYield 64%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

16.5 g of an 80% by weight suspension of sodium hydride in white oil (corresponding to 0.55 mol of NaH) were mixed with 500 ml of anhydrous tetrahydrofuran and, while stirring efficiently at 50° to 60° C., a mixture of 81 g (corresponding to 0.5 mol) of p-methoxycinnamaldehyde and 65 g (corresponding to 0.5 mol) of methyl β-methoxycrotonate was added dropwise. The rate of this dropwise addition was chosen so that the mixture continued to boil gently. It was then stirred at 65° C. for 3 hours and subsequently at room temperature overnight. To work up the reaction mixture was cooled and mixed with 0.5 l of ice-water and then extracted with methyl tertbutyl ether. The remaining alkaline aqueous phase was acidified with dilute hydrochloric acid while cooling in ice, and the precipitate was filtered off and thoroughly washed with water. Drying resulted in 83 g of the title compound of melting point 187° C. (after recrystallization from ethyl acetate), corresponding to a yield of 64%.

Workup

  1. additionwas added dropwise
  2. additionThe rate of this dropwise addition
  3. stirringIt was then stirred at 65° C. for 3 hours and subsequently at room temperature overnight
  4. temperaturewas cooled
  5. extractionextracted with methyl tertbutyl ether
  6. temperaturewhile cooling in ice
  7. filtrationthe precipitate was filtered off
  8. washthoroughly washed with water
  9. customDrying

Sources & evidence

ORD record
ord-5eb82f6e4d204b6d8147f0d514030383
Source dataset
uspto-grants-1994_06
Patent number
US05320833

Reaction notes

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