Benzene → 1-Methyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid methyl ester

HRID 616963Notes

Reaction equation

HRID 616963 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]([CH2:10][CH2:11][SH:12])=[CH:2]1.[C:13]([O:19][CH3:20])(=[O:18])[CH2:14][C:15]([CH3:17])=O.C1C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>O>[CH3:20][O:19][C:13](=[O:18])[CH2:14][C:15]1([CH3:17])[C:2]2[NH:1][C:9]3[C:4]([C:3]=2[CH2:10][CH2:11][S:12]1)=[CH:5][CH:6]=[CH:7][CH:8]=3

Participants

6

Reactant 4

HCID 241BenzeneHCID 6101p-Toluenesulfonic acidHCID 7757Methyl acetoacetateHCID 122442792-(1H-indol-3-yl)ethane-1-thiol

Product 1

HCID 538355841-Methyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid methyl ester

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Indole-3-ethanethiol (1.5 g.) and methyl acetoacetate are mixed with 50 ml. of benzene and the solution heated for 30 min. (bath temperature 70°-80° C.). p-Toluenesulfonic acid (0.15 g.) is added and the reaction mixture is subjected to reflux and stirring for 12 hours. Water formed in the reaction mixture during this period is collected by a water separator. After cooling the benzene solution is washed with a 10% solution of sodium bicarbonate, water, saturated brine and dried over sodium sulfate. Evaporation of the benzene solution yields the ester, 1-methyl-1,3,4,9-tetrahydrothiopyrano[3,4-b]indole-1-acetic acid methyl ester as a semi-solid, δmaxCHCl3 1715 cm-1.

Workup

  1. temperatureto reflux
  2. customis collected by a water separator
  3. temperatureAfter cooling the benzene solution
  4. washis washed with a 10% solution of sodium bicarbonate, water, saturated brine
  5. dry with materialdried over sodium sulfate
  6. customEvaporation of the benzene solution

Sources & evidence

ORD record
ord-370cff3f0a5a49059aef36e7b8fdda8e
Source dataset
uspto-grants-1978_02
Patent number
US04076831

Reaction notes

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