Methanol → tert-Butyl ethyl(2-(7-nitro-2H-benzo[b][1,4]oxazin-4(3H)-yl)ethyl)carbamate

HRID 424479Notes

Reaction equation

HRID 424479 reaction equation
[CH2:1]([N:3]([CH2:11][C:12]([N:14]1[CH2:19][CH2:18][O:17][C:16]2[CH:20]=[C:21]([N+:24]([O-:26])=[O:25])[CH:22]=[CH:23][C:15]1=2)=O)[C:4](=[O:10])[O:5][C:6]([CH3:9])([CH3:8])[CH3:7])[CH3:2].B.C1COCC1.CO>C1COCC1>[CH2:1]([N:3]([CH2:11][CH2:12][N:14]1[CH2:19][CH2:18][O:17][C:16]2[CH:20]=[C:21]([N+:24]([O-:26])=[O:25])[CH:22]=[CH:23][C:15]1=2)[C:4](=[O:10])[O:5][C:6]([CH3:9])([CH3:7])[CH3:8])[CH3:2]

Participants

5

Reactant 3

HCID 887MethanolHCID 2723981Borane;tetrahydrofuranHCID 59144071tert-butyl ethyl(2-(7-nitro-2H-benzo[b][1,4]oxazin-4(3H)-yl)-2-oxoethyl)carbamate

Product 1

HCID 59144101tert-Butyl ethyl(2-(7-nitro-2H-benzo[b][1,4]oxazin-4(3H)-yl)ethyl)carbamateYield 91%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A yellow solution of tert-butyl ethyl(2-(7-nitro-2H-benzo[b][1,4]oxazin-4(3H)-yl)-2-oxoethyl)carbamate (8.7 g, 23.8 mmol) in anhydrous THF (50 mL) under positive argon pressure was treated with borane-THF complex (1M in THF, 47.6 mL, 47.6 mmol) to give an orange solution. The mixture was refluxed for 20 minutes. It was then cooled in an ice bath and treated dropwise with MeOH (100 mL). The solution stirred for half an hour at room temperature, and the reaction was then concentrated. The residue was subjected to flash chromatography on silica gel using 1:9 EtOAc:hexanes to give an orange solid (7.5 g, 91%). 1H-NMR (DMSO-d6) δ 7.72 (dd, J=2.7, 9.0 Hz, 1H), 7.49-7.47 (m, 1H), 6.85-6.83 (m, 1H), 4.18 (t, J=4.2 Hz, 2H), 3.59-3.53 (m, 2H), 3.37-3.36 (m, 2H), 3.20-3.18 (m, 2H), 1.47 (s, 2H), 1.30 (br s, 9H), 1.02 (t, J=6.9 Hz, 3H); ESI-MS (m/z, %): 374 (MNa+, 86), 352 (MH+, 7.8), 296 (100), 252 (87).

Workup

  1. customto give an orange solution
  2. temperatureThe mixture was refluxed for 20 minutes
  3. temperatureIt was then cooled in an ice bath
  4. concentrationthe reaction was then concentrated

Sources & evidence

ORD record
ord-e0b6efdf35ae4690a91fc7bcf3cd1197
Source dataset
uspto-grants-2012_01
Patent number
US08106043B2

Reaction notes

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