Tryptophol → 1-(Acetamidomethyl)-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole

HRID 1438743Notes

Reaction equation

HRID 1438743 reaction equation
[CH:1]1[CH:2]=[CH:3][C:4]2[NH:9][CH:8]=[C:7]([CH2:10][CH2:11][OH:12])[C:5]=2[CH:6]=1.[C:13]([NH:16][CH2:17][C:18](=O)[CH3:19])(=[O:15])[CH3:14]>C1C=CC=CC=1>[C:13]([NH:16][CH2:17][C:18]1([CH3:19])[C:8]2[NH:9][C:4]3[C:5]([C:7]=2[CH2:10][CH2:11][O:12]1)=[CH:6][CH:1]=[CH:2][CH:3]=3)(=[O:15])[CH3:14]

Participants

4

Reactant 2

HCID 10685TryptopholHCID 82185N-(2-oxopropyl)acetamide

Product 1

HCID 127081801-(Acetamidomethyl)-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A mixture of tryptophol (3.86 g; II, R2, R3, R4, R5, R6 = H and X1 = OH) and acetamidoacetone (3.0 g), see R. H. Wileg and O. H. Borum, J. Amer. Chem. Soc., 70, 2005 (1948), in 300 ml of dry benzene is stirred and heated to reflux. Water is collected in a Dean-Stark trap. After removal of the water five drops of boron trifluoride-etherate is added and the mixture refluxed 30 min. using the water-separator again. After stirring at room temperature overnight, the reaction mixture is evaporated to dryness. The solid residue is dissolved in chloroform and washed successively with 10% aqueous sodium bicarbonate, water, and brine. The chloroform solution is dried over magnesium sulfate, filtered, and evaporated. The residue is crystallized from benzene to yield 1-(acetamidomethyl)-1-methyl-1,3,4,9-tetrahydropyrano[3,4-b]indole, m.p. 100° - 102° C. This product is dried under reduced pressure at 27° C. Spectroscopic and analytical data show that the compound is solvated with one mole of benzene which can be removed completly only by melting. Rf values of the amide and tryptophol are equal.

Workup

  1. temperatureheated to reflux
  2. customWater is collected in a Dean-Stark trap
  3. customAfter removal of the water five drops of boron trifluoride-etherate
  4. additionis added
  5. temperaturethe mixture refluxed 30 min.
  6. customthe reaction mixture is evaporated to dryness
  7. dissolutionThe solid residue is dissolved in chloroform
  8. washwashed successively with 10% aqueous sodium bicarbonate, water, and brine
  9. dry with materialThe chloroform solution is dried over magnesium sulfate
  10. filtrationfiltered
  11. customevaporated
  12. customThe residue is crystallized from benzene

Sources & evidence

ORD record
ord-36595d2e724d4f1387380c91c297c553
Source dataset
uspto-grants-1977_11
Patent number
US04056537

Reaction notes

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