Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Hydrochloric Acid | HCID 313 | — |
| Reactant | Cyclohexanecarboxaldehyde | HCID 16275 | — |
| Reactant | Sodium borohydride | HCID 4311764 | — |
| Reactant | Crisaborole intermediate | HCID 57968923 | — |
| Solvent | Ethanol | HCID 702 | — |
| Product | HCID 57968790 | HCID 57968790 | — |
Reaction Steps
To a solution of 5-(4-aminomethyl-phenoxy)-3H-benzo[c][1,2]oxaborol-1-ol (150 mg, 0.59 mmol, 1.0 eq.) in EtOH (5.0 mL) was added cyclohexanecarbaldehyde (280 μL, 2.36 mmol, 4.0 eq.). The mixture was stirred at room temperature for 30 minutes. After cooling to 0° C., NaBH4 (89 mg, 0.36 mmol, 4.0 eq.) was added in portions and the mixture was allowed to warm to room temperature and stirred for 2 h. The mixture was carefully treated with dilute HCl (5 mL) and aqueous phase was extracted with EtOAc (3×10 mL). Combined organic extracts was washed with brine (10 mL), dried over MgSO4, filtered and the filtrate was concentrated under reduced pressure. The residue was applied to silica chromatography eluting with MeOH/DCM (0:100 to 10:90) to give 5-{4-[(cyclohexylmethyl-amino)-methyl]-phenoxy}-3H-benzo[c][1,2]oxaborol-1-ol as a white solid. LCMS (m/z) 352 (M+H); 1H NMR (DMSO-d6) δ: 9.08 (s, 1H), 7.68 (d, J=8.0 Hz, 1H), 7.30-7.37 (m, J=8.5 Hz, 2H), 6.95-7.02 (m, 2H), 6.88-6.95 (m, 2H), 4.89 (s, 2H), 3.64 (s, 2H), 2.31 (d, J=6.6 Hz, 2H), 1.67-1.77 (m, 2H), 1.56-1.66 (m, 3H), 1.30-1.44 (m, 1H), 1.02-1.23 (m, 3H), 0.77-0.91 (m, 2H).
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US09012431B2 |
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| Source dataset | uspto-grants-2015_04 |
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| ORD ID | ord-b8a1cab6628f44f68469afac647ff6b8 |
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| Source note | uspto-grants-2015_04 |
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