Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Imidazole | HCID 795 | — |
| Reactant | tert-Butyldimethylsilyl chloride | HCID 28928 | — |
| Reactant | HCID 69411353 | HCID 69411353 | — |
| Solvent | Dimethylformamide | HCID 6228 | — |
| Product | HCID 69410951 | HCID 69410951 | 90.5% |
Reaction Steps
3β-Hydroxy-4,4-dimethyl-5α-chola-8,14-dien-24-oic acid methyl ester (18.2 g) is suspended in 400 ml of DMF and 14.8 g of imidazol and 13.0 g of t-butyldimethylsilylchloride is added. The reaction is stirred at 65° C. for 20 hours. After aqueous work-up and crystallization from ether/methanol, 3β-tert-butyldimethylsilyloxy-4,4-dimethyl-5α-chola-8,14-dien-24-oic acid methyl ester (21 g) is obtained. Melting point: 124-125° C. 1H-NMR (CDCl3, 400 MHz): δ=5.34 (1H, s); 3.68 (3H, s); 3.2 (1H, m); 0.9 (9H, s); 0.04 (6H, m).
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
|---|
| Patent number | US06884796B2 |
|---|
| Source dataset | uspto-grants-2005_04 |
|---|
| ORD ID | ord-1ab8a1b9b9ce43e1b33bcf7e26d1f458 |
|---|
| Source note | uspto-grants-2005_04 |
|---|
