Acetone → 6-Benzyloxy-1,1-dimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole

HRID 37703

Reaction equation

HRID 37703 reaction equation
[CH:1]1[CH:6]=[CH:5][C:4]([CH2:7][O:8][C:9]2[CH:14]=[CH:13][C:12]3[NH:15][CH:16]=[C:17]([CH2:18][CH2:19][OH:20])[C:11]=3[CH:10]=2)=[CH:3][CH:2]=1.[CH3:21][C:22]([CH3:24])=O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH3:21][C:22]1([CH3:24])[C:16]2[NH:15][C:12]3[C:11]([C:17]=2[CH2:18][CH2:19][O:20]1)=[CH:10][C:9]([O:8][CH2:7][C:4]1[CH:3]=[CH:2][CH:1]=[CH:6][CH:5]=1)=[CH:14][CH:13]=3

Participants

5

Reactant 3

HCID 180AcetoneHCID 6101p-Toluenesulfonic acidHCID 7448495-Benzyloxy-3-(2-hydroxyethyl)indole

Product 1

HCID 199357106-Benzyloxy-1,1-dimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A mixture consisting of 5-benzyloxytryptophol (3.2 g, 0.012 mol), acetone (7 mL), benzene (300 mL) and p-toluene sulfonic acid (500 mg) is refluxed for 3.5 hours using a Dean-Stark trap to remove the water. The reaction mixture is cooled to room temperature and washed with 5% sodium bicarbonate (1×200 mL), water (200 mL) and brine (200 mL). It is dried (MgSO4), filtered and concentrated to give 5.0 g product as thick oil. The crude product is flash chromatographed with 15% ethyl acetate/hexane as an eluent to afford 2.5 g product, m.p. 128°-129° C.

Workup

  1. temperatureis refluxed for 3.5 hours
  2. customto remove the water
  3. washwashed with 5% sodium bicarbonate (1×200 mL), water (200 mL) and brine (200 mL)
  4. dry with materialIt is dried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-04c69628f10c4cdcac7f0d26a8895db8
Source dataset
uspto-grants-1995_05
Patent number
US05420289

Linked notes

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