Acetone → Methyl 2-methylazulene-1-carboxylate

HRID 1721461Notes

Reaction equation

HRID 1721461 reaction equation
[CH3:1][O:2][C:3]([C:5]1C(=O)O[C:7]2=[CH:11][CH:12]=[CH:13][CH:14]=[CH:15][C:6]=12)=[O:4].[CH3:16]C(C)=O.C(N[CH2:23][CH3:24])C>O>[CH3:1][O:2][C:3]([C:5]1[C:6]2[C:7]([CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=2)=[CH:16][C:23]=1[CH3:24])=[O:4]

Participants

5

Reactant 3

HCID 180AcetoneHCID 8021DiethylamineHCID 10081616Methyl 2-oxo-2H-cyclohepta[b]furan-3-carboxylate

Product 1

HCID 11264110Methyl 2-methylazulene-1-carboxylate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

2-Methylazulene was synthesized according to a method described in Japanese Patent Laid-Open Publication No. 207232/1987. Specifically, 19.5 g (0.16 mol) of tropolone was reacted with 40 g (0.21 mol) of p-toluenesulfonic acid chloride in pyridine to give 37.1 g of tosylated tropolone. Then, 20 g (0.15 mol) of dimethylmalonate was reacted with 9.7 g (0.18 mol) of NaOMe in methanol at room temperature for 4 hr to give 14.4 g of 3-methoxycarbonyl-2H-cyclohepta(b) furan-2-one (Compound (2)). Then, 12 g of Compound (2), 200 ml of acetone and 70 ml of diethylamine were added, and the mixture was heated under reflux for 30 hr. Thereafter, H2O was added thereto, and the mixture was extracted with toluene to give 39.2 g of methyl-2-methylazulene carboxylate. Further, 25 ml of phosphoric acid was added, and a reaction was allowed to proceed at 85° to 90° C. for one hr. The reaction mixture was decomposed with water, extracted with benzene and dried to give 6.5 g of 2-methylazulene as an intended product.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 30 hr
  3. extractionthe mixture was extracted with toluene

Sources & evidence

ORD record
ord-5c7093494559404f8ca1135715b75507
Source dataset
uspto-grants-1996_04
Patent number
US05510502

Reaction notes

Loading…