Hydrochloric Acid → 1H-Inden-4-ol

To a solution of 4-(tert-butyldimethylsiloxy)-1-indanone (35.0 g, 133 mmol) in methanol/THF (100 ml:200 ml) was NaBH4 (7.57 g, 200 mmol) added in portions at 0° C. The reaction mixture is stirred overnight. The resulting solution is poured on ice, acidified with concentrated hydrochloric acid to pH=1 and extracted with diethyl eter (2×200 ml). The organic fractions were combined and washed with brine, water and dried over sodiumsulfate. The solvents were evaporated and the remaining oil (siloxyindanol) was dissolved in toluene (300 ml). To this solution was oxalic acid (24.0 g, 267 mmol) added. The mixture was heated under reflux for 3 hours, whereafter the reaction mixture was washed with a 10% aqueous solution of NaHCO3 and dried over sodiumsulfate. The solvent was removed by evaporation. The remaining yellow oil was dissolved in THF (300 ml) and treated with tetra-n-butylammonium fluoride (69.6 g, 266 mmol) at 0° C. and stirred for 30 min at room temperature. The reaction solution was treated with a saturated NH4Cl solution (200 ml) and extracted with diethyl ether (2×200 ml) The organic phase was collected, evaporation of solvent left a solid which was recrystallized from methanol to give a pale yellow solid (11.45 g, 86.6 mmol, 65.10%).

1. additionadded in portions at 0° C
2. additionThe resulting solution is poured on ice
3. extractionextracted with diethyl eter (2×200 ml)
4. washwashed with brine, water
5. dry with materialdried over sodiumsulfate
6. customThe solvents were evaporated
7. dissolutionthe remaining oil (siloxyindanol) was dissolved in toluene (300 ml)
8. additionadded
9. temperatureThe mixture was heated
10. temperatureunder reflux for 3 hours, whereafter the reaction mixture
11. washwas washed with a 10% aqueous solution of NaHCO3
12. dry with materialdried over sodiumsulfate
13. customThe solvent was removed by evaporation
14. dissolutionThe remaining yellow oil was dissolved in THF (300 ml)
15. stirringstirred for 30 min at room temperature
16. extractionextracted with diethyl ether (2×200 ml) The organic phase
17. customwas collected
18. customevaporation of solvent
19. waitleft a solid which
20. customwas recrystallized from methanol

ORD record

ord-2eff2f10331b4e68bad3123965ac0956

Source dataset

uspto-grants-2006_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07074863B2