Reaction #1960500

Reaction equation

6-(1-ethynylbutoxy)-7,8-difluoro-2-(4-propylcyclohexyl)-1,2,3,4-tetrahydronaphthalene

hydrochloric acid

→

5,6-difluoro-3-propyl-8-(4-propylcyclohexyl)-7,8,9,10-tetrahydro-3H-benzo[f]chromene

Solvents

N,N-diethylaniline

Conditions

Workup

1. 1
   TemperatureAfter cooling
2. 2
   Extractionthe mixture is extracted with MTBE
3. 3
   WashThe organic phase is washed with 2 N hydrochloric acid and water
4. 4
   Otherthe solution is dried
5. 5
   Otherafter removal of the solvent
6. 6
   Otheris purified by column chromatography (SiO2, n-heptane:toluene=9:1)

Procedure

4.5 g (11.6 mmol) of 6-(1-ethynylbutoxy)-7,8-difluoro-2-(4-propylcyclohexyl)-1,2,3,4-tetrahydronaphthalene are heated at 200° C. for 2 h in 45 ml of N,N-diethylaniline. After cooling, the batch is added to a mixture of 2 N hydrochloric acid and ice, and the mixture is extracted with MTBE. The organic phase is washed with 2 N hydrochloric acid and water, and the solution is dried using sodium sulfate. The residue remaining after removal of the solvent is purified by column chromatography (SiO2, n-heptane:toluene=9:1), giving 5,6-difluoro-3-propyl-8-(4-propylcyclohexyl)-7,8,9,10-tetrahydro-3H-benzo[f]chromene as a yellow solid.

Source