Sulfuric Acid → ethyl 5,6,7,8-tetrahydro-11-chloro-8-methoxy-4H-azocino [3,2,1-hi]indole-2-carboxylate

HRID 1600639Notes

Reaction equation

[Cl:1][C:2]1[CH:10]=[CH:9][C:8]2[CH:11]([OH:16])[CH2:12][CH2:13][CH2:14][CH2:15][N:6]3[C:7]=2[C:3]=1[CH:4]=[C:5]3[C:17]([O:19][CH2:20][CH3:21])=[O:18].F[C:23]1C(C)=C(C=C(N=[N+]=[N-])C(OCC)=O)C=CC=1.S(=O)(=O)(O)O>CO>[Cl:1][C:2]1[CH:10]=[CH:9][C:8]2[CH:11]([O:16][CH3:23])[CH2:12][CH2:13][CH2:14][CH2:15][N:6]3[C:7]=2[C:3]=1[CH:4]=[C:5]3[C:17]([O:19][CH2:20][CH3:21])=[O:18]

Participants

Conditions

Temperature: 0 °C

Procedure

The ethyl 5,6,7,8-tetrahydro-11-chloro-8-hydroxy-4H-azocino[3,2,1-hi]indole-2-carboxylate (1.90 g, 6.17 mmol) obtained in Example 23, (a) was added to a mixture of methanol (19 ml) and concentrated sulfuric acid (1.89 g) which had been cooled to 0° C. The reaction mixture was heated to 40° C. and stirred for 1 hour. The reaction mixture was poured into ice water and extracted twice with ethyl acetate, and the extract solution was washed twice with a 5% aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the resulting residue was purified by a silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/99) to obtain 1.96 g of ethyl 5,6,7,8-tetrahydro-11-chloro-8-methoxy-4H-azocino-[3,2,1-hi]indole-2-carboxylate as a colorless oil.

Workup

temperatureThe reaction mixture was heated to 40° C.
extractionextracted twice with ethyl acetate
washthe extract solution was washed twice with a 5% aqueous sodium chloride solution
dry with materialdried over anhydrous magnesium sulfate
distillationThe solvent was distilled off under reduced pressure
customthe resulting residue was purified by a silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/99)

Sources & evidence

ORD record: ord-4c34563fba53443b9b887d1b4dd1dbb5
Source dataset: uspto-grants-1999_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05977100

Reaction notes

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