Hydrochloric Acid → 2-Hydroxy-4-methylbenzaldehyde

HRID 1492760Notes

Reaction equation

HRID 1492760 reaction equation
C(Br)C.[Mg].[CH:5]1[C:10]([OH:11])=[CH:9][CH:8]=[CH:7][C:6]=1[CH3:12].[CH2:13]=[O:14].Cl>C1COCC1.C1(C)C=CC=CC=1.CN1CCCN(C)C1=O>[OH:11][C:10]1[CH:5]=[C:6]([CH3:12])[CH:7]=[CH:8][C:9]=1[CH:13]=[O:14]

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 342M-CresolHCID 712FormaldehydeHCID 6332Ethyl BromideHCID 5462224Magnesium

Product 1

HCID 612002-Hydroxy-4-methylbenzaldehydeYield 21.1%

Reagents, catalysts & solvents 3

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent3×HCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-Solvent

Procedure

A solution of ethyl bromide (13.8 ml) in THF (100 ml) was added dropwise, under nitrogen to a stirred mixture of magnesium turnings (4.44 g) in dry THF (50 ml). After complete Grignard formation a solution of m-cresol (20 g) in THF (100 ml) was added dropwise. The resulting suspension was stirred for 15 mins before a solution of 1,3-dimethyl-3,4,5,6-tetrahydropyrimidin-2-one (23.7 g) in dry toluene (300 ml) was added dropwise followed by paraformaldehyde (13.85 g). The resulting suspension was heated at reflux overnight. After cooling the suspension was treated with 10% HCl (200 ml) and filtered before separating the organic phase. The organic extracts were washed with water (4×100 ml), dried and evaporated to a yellow crystalline solid (11 g). Low temperature crystallisation from ether gave the title compound as a white crystalline solid (5.31 g). A second crop (0.695 g) was also obtained.

Workup

  1. additionwas added dropwise
  2. temperatureThe resulting suspension was heated
  3. temperatureat reflux overnight
  4. temperatureAfter cooling the suspension
  5. filtrationfiltered
  6. custombefore separating the organic phase
  7. washThe organic extracts were washed with water (4×100 ml)
  8. customdried
  9. customevaporated to a yellow crystalline solid (11 g)
  10. customLow temperature crystallisation from ether

Sources & evidence

ORD record
ord-ddd6dde72bcd4791b2a340638a2f8602
Source dataset
uspto-grants-1994_12
Patent number
US05374646

Reaction notes

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