Sodium triacetoxyborohydride → HCID 59144109, compound

HRID 424494Notes

Reaction equation

HRID 424494 reaction equation
[CH3:1][N:2]([CH2:10][CH:11]=O)[C:3](=[O:9])[O:4][C:5]([CH3:8])([CH3:7])[CH3:6].[N+:13]([C:16]1[CH:25]=[CH:24][C:19]2[O:20][CH2:21][CH2:22][NH:23][C:18]=2[CH:17]=1)([O-:15])=[O:14].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>C(O)(=O)C.ClCCCl>[CH3:1][N:2]([CH2:10][CH2:11][N:23]1[CH2:22][CH2:21][O:20][C:19]2[CH:24]=[CH:25][C:16]([N+:13]([O-:15])=[O:14])=[CH:17][C:18]1=2)[C:3](=[O:9])[O:4][C:5]([CH3:6])([CH3:7])[CH3:8]

Participants

6

Reactant 3

HCID 5049666Sodium triacetoxyborohydrideHCID 70622256-nitro-3,4-dihydro-2H-1,4-benzoxazineHCID 10725881tert-butyl N-methyl-N-(2-oxoethyl)carbamate

Product 1

HCID 59144109HCID 59144109, compound

Reagents, catalysts & solvents 2

HCID 111,2-DichloroethaneSolventHCID 176Acetic AcidSolvent2×

Procedure

To an oven dried, argon purged flask fitted with a magnetic stirbar was added tert-butyl methyl(2-oxoethyl)carbamate (0.135 g, 0.777 mmol), and DCE (10 mL). At this time, stirring began, and 6-nitro-3,4-dihydro-2H-benzo[b][1,4]oxazine (0.10 g, 0.555 mmol) was added, followed by acetic acid (0.064 mL, 1.110 mmol) and sodium triacetoxyborohydride (0.294 g, 1.388 mmol). The resulting mixture stirred overnight at room temperature. After 18 hours, the reaction was quenched by the addition of saturated NaHCO3 (10 mL) and extracted with CH2Cl2. The aqueous layer was extracted further, and the combined organics were washed with brine, dried (Na2SO4), and concentrated. The crude product was combined with the product of a second reaction (prepared in accordance with the above procedure, with the omission of acetic acid). The combined products were purified on silica gel eluting with 50-70% EtOAc/hexanes to yield the title compound as a yellow residue (130 mg, 34.7%). 1H NMR (DMSO-d6) δ 7.58-7.37 (m, 2H), 6.92-6.80 (m, 1H), 4.25 (t, 2H, J=4.2 Hz), 3.58-3.36 (m, 6H), 2.87-2.74 (m, 3H), 1.27, 1.18 (2×s, 9H); ESI-MS (m/z, %): 360 (MNa+, 100).

Workup

  1. customTo an oven dried
  2. customargon purged flask fitted with a magnetic stirbar
  3. stirringThe resulting mixture stirred overnight at room temperature
  4. customthe reaction was quenched by the addition of saturated NaHCO3 (10 mL)
  5. extractionextracted with CH2Cl2
  6. extractionThe aqueous layer was extracted further
  7. washthe combined organics were washed with brine
  8. dry with materialdried (Na2SO4)
  9. concentrationconcentrated
  10. customThe crude product was combined with the product of a second reaction (
  11. customThe combined products were purified on silica gel eluting with 50-70% EtOAc/hexanes

Sources & evidence

ORD record
ord-77d90fbfaa6447d08f44b4cc42b2c4db
Source dataset
uspto-grants-2012_01
Patent number
US08106043B2

Reaction notes

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