Water → 6,7,8,9-tetrahydro-1H-benzo[g]indole

HRID 2253263Notes

Reaction equation

[H-].[Al+3].[Li+].[H-].[H-].[H-].[NH:7]1[C:15]2[C:10](=[CH:11][CH:12]=[C:13]3[CH2:19][CH2:18][CH2:17][CH2:16][C:14]3=2)[C:9](=O)[C:8]1=O.O.[OH-].[Na+]>O1CCCC1>[NH:7]1[C:15]2[C:10](=[CH:11][CH:12]=[C:13]3[CH2:19][CH2:18][CH2:17][CH2:16][C:14]3=2)[CH:9]=[CH:8]1

Participants

Conditions

Temperature: 0 °C

Procedure

To a suspension of lithium aluminium hydride (2.85 g, 75.0 mmol) in dry tetrahydrofuran (150 mL) was added 6,7,8,9-tetrahydro-1H-benz[g]indole-2,3-dione (3.018 g, 15.0 mmol) portionwise over 30 min. The green suspension was heated under reflux for 18 h and then cooled to 0° C. The suspension was treated with water (2.8 mL), 5 N aqueous sodium hydroxide (2.1 mL), and water (9.2 mL), and was stirred for an additional 1 h. The suspension was then filtered, the residue was washed with tetrahydrofuran. and the filtrate then concentrated in vacuo. The residue obtained was purified by column chromatography [SiO2; ethyl acetate-heptane (1:19)] and triturated with hexane to give the title indole (1.58 g, 62%) as a white solid: mp. 93-94° C. (lit. [Khim. Geterotsikl. Soedin., 1978, 14, 634] 89-90° C.); Found: C, 84.25; H. 7.65; N, 8.16%. C12H13N requires C, 84.17; H, 7.65; N, 8.18%.

Workup

temperatureThe green suspension was heated
temperatureunder reflux for 18 h
filtrationThe suspension was then filtered
washthe residue was washed with tetrahydrofuran
concentrationand the filtrate then concentrated in vacuo
customThe residue obtained
customwas purified by column chromatography [SiO2; ethyl acetate-heptane (1:19)]
customtriturated with hexane

Sources & evidence

ORD record: ord-509451fc99bf481b9680b7c1fb0b4a20
Source dataset: uspto-grants-2008_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07323487B2

Reaction notes

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