Methyl 3-oxovalerate → Methyl 1,8-diethyl-1,3,4,9-tetrahydropyrano(3,4-b)indole-1-acetate

HRID 2270452Notes

Reaction equation

HRID 2270452 reaction equation
[CH3:1][CH2:2][C:3]1[C:8]2[NH:9][CH:10]=[C:11]([CH2:12][CH2:13][OH:14])[C:7]=2[CH:6]=[CH:5][CH:4]=1.O=[C:16]([CH2:22][CH3:23])[CH2:17][C:18]([O:20][CH3:21])=[O:19]>Cl>[CH2:22]([C:16]1([CH2:17][C:18]([O:20][CH3:21])=[O:19])[C:10]2[NH:9][C:8]3[C:7]([C:11]=2[CH2:12][CH2:13][O:14]1)=[CH:6][CH:5]=[CH:4][C:3]=3[CH2:2][CH3:1])[CH3:23]

Participants

4

Reactant 2

HCID 121699Methyl 3-oxovalerateHCID 1982317-Ethyltryptophol

Product 1

HCID 527310Methyl 1,8-diethyl-1,3,4,9-tetrahydropyrano(3,4-b)indole-1-acetateYield 79%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Conditions

Temperature
27.5 °C

Procedure

To a solution of 7-ethyltryptophol (12.0 g) in 1-butanolic hydrogen chloride (5% w/v, 100.0 ml), methyl 3-oxopentanoate (9.1 g) was added in one lot, at 25° C. The reaction mixture was stirred at 25-30° C. for 7 hours. The reaction mixture was extracted with hexane (100.0 ml). Hexane was concentrated to about 20 ml and methanol (10 ml) was added. The product was filtered, washed with methanol and dried to afford the titled compound (14.7 g, 79%), m.p. 128-130° C.; purity: 96.2%.

Workup

  1. extractionThe reaction mixture was extracted with hexane (100.0 ml)
  2. concentrationHexane was concentrated to about 20 ml and methanol (10 ml)
  3. additionwas added
  4. filtrationThe product was filtered
  5. washwashed with methanol
  6. customdried

Sources & evidence

ORD record
ord-a2dc2fd1d57d472e8baa07739226bfe8
Source dataset
uspto-grants-2001_12
Patent number
US06331638B1

Reaction notes

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