Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Hydrochloric Acid | HCID 313 | — |
| Reactant | Boron trifluoride etherate | HCID 8000 | — |
| Reactant | Sodium Bicarbonate | HCID 516892 | — |
| Reactant | Sodium borohydride | HCID 4311764 | — |
| Reactant | Methyl 3-oxo-3,4-dihydro-2H-1,4-benzoxazine-8-carboxylate | HCID 23770643 | — |
| Solvent | Tetrahydrofuran | HCID 8028 | — |
| Solvent | Ethyl Acetate | HCID 8857 | — |
| Product | HCID 16244454 | HCID 16244454 | — |
Reaction Steps
Boron trifluoride diethyl etherate (10.1 mmol) is added dropwise to a mixture of 3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-8-carboxylic acid methyl ester (4.83 mmol) in THF (12 mL) to keep the temperature below 5° C. After 20 min NaBH4 (10.1 mmol) is added and the mixture is stirred at 5° C. for 60 min. EtOAc (6.0 mL) and hydrochloric acid (1.0 M, 6.0 mL) are added dropwise. The mixture is made basic by addition of sat. aq. NaHCO3 solution, the layers are separated and the aq. layer is extracted with EtOAc. The combined organic layers are dried over MgSO4 and concentrated in vacuo to give a crude product which is purified by CC (heptane to heptane/EtOAc 3/7). LC-MS: tR=0.69 min; [M+H]+=194.0.
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US08288435B2 |
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| Source dataset | uspto-grants-2012_10 |
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| ORD ID | ord-052ba936a60b4100a318775332611fa7 |
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| Source note | uspto-grants-2012_10 |
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