8-ethoxy-5,6-difluoro-3-(4-propylcyclohexyl)-3H-benzo[f]chromene → 8-ethoxy-5,6-difluoro-3-(4-propylcyclohexyl)-2,3-dihydro-1H-benzo[f]chromene
Reaction equation
[CH2:1]([O:3][C:4]1[CH:28]=[CH:27][C:7]2[C:8]3[CH:9]=[CH:10][CH:11]([CH:18]4[CH2:23][CH2:22][CH:21]([CH2:24][CH2:25][CH3:26])[CH2:20][CH2:19]4)[O:12][C:13]=3[C:14]([F:17])=[C:15]([F:16])[C:6]=2[CH:5]=1)[CH3:2]>C1COCC1.[Pd]>[CH2:1]([O:3][C:4]1[CH:28]=[CH:27][C:7]2[C:8]3[CH2:9][CH2:10][CH:11]([CH:18]4[CH2:23][CH2:22][CH:21]([CH2:24][CH2:25][CH3:26])[CH2:20][CH2:19]4)[O:12][C:13]=3[C:14]([F:17])=[C:15]([F:16])[C:6]=2[CH:5]=1)[CH3:2]Participants
4
Procedure
5.1 g (13.1 mmol) of 8-ethoxy-5,6-difluoro-3-(4-propylcyclohexyl)-3H-benzo[f]chromene are hydrogenated at atmospheric pressure in THF and in the presence of Pd/C (5% of Pd). The reaction solution is filtered, and the filtrate is evaporated to dryness. The residue is recrystallised from ethyl acetate, giving 8-ethoxy-5,6-difluoro-3-(4-propylcyclohexyl)-2,3-dihydro-1H-benzo[f]chromene as a colourless solid (m.p. 158° C.).