ChemicalBook CAS DataBase List 5,6,7,8-Tetrahydro-2-naphthol

5,6,7,8-Tetrahydro-2-naphthol synthesis

10synthesis methods

Product Name:5,6,7,8-Tetrahydro-2-naphthol
CAS Number:1125-78-6
Molecular formula:C10H12O
Molecular Weight:148.2

1730-48-9
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$44.00/5mL

1125-78-6
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$18.00/10g

Yield:1125-78-6 57.4%

Reaction Conditions:

Stage #1:6-methoxy-1,2,3,4-tetrahydronaphthalene with aluminum (III) chloride;thiourea at 90; for 1 h;
Stage #2: with hydrogenchloride in water;1,2-dichloro-ethane at 0 - 20;

Steps:

17
Example 17; Preparation of 5,6,7,8-tetrahydro-2-naphthol by demethylation of 5,6,7,8-tetrahydro-2- -methoxynaphthalene of the formula (VIII) CH₃(VIII)To a mixture of 5.67 g (42.5 mmol) of aluminium chloride and 2.28 g (30 mmol) of thiourea 1.62 g (10 mmol) of 5,6,7,8-tetrahydro-2-methoxynaphthalene is added. The reaction mixture is heated to 90°C and maintained at this temperature for 1 hour, then cooled to room temperature, 20 ml of 1,2-dichloroethane is added and the mixture is poured onto 20 ml of 5 wt % hydrochloric acid/ice mixture.The mixture is stirred for a few minutes, then the phases are separated. The aqueous layer is extracted with 20 ml of 1,2-dichloroethane. The combined dichloroethane phases are washed with 3 x 10 ml of 5 % aqueous sodium hydroxide. The combined alkaline phases are acidified with 18 wt % hydrochloric acid solution, then extracted with 3 x 10 ml of dichloromethane. The combined dichloromethane phases are washed with water, dried over sodium sulfate and evaporated yielding 0.85 g (57.4) of 5,6,7, 8-tetrahydro-2-naphthol.

References:

RICHTER GEDEON VEGYéSZETI GYáR RT. WO2006/61666, 2006, A2 Location in patent:Page/Page column 20

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