Nitrogen → 4-Allyl-5-chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine

HRID 1400720Notes

Reaction equation

HRID 1400720 reaction equation
[Cl:1][C:2]1[C:11]2[NH:10][CH2:9][CH2:8][O:7][C:6]=2[CH:5]=[CH:4][C:3]=1[B:12]1[O:16][C:15]([CH3:18])([CH3:17])[C:14]([CH3:20])([CH3:19])[O:13]1.C([O-])([O-])=O.[K+].[K+].N#N.[CH2:29](Br)[CH:30]=[CH2:31]>CN(C=O)C.O>[CH2:31]([N:10]1[CH2:9][CH2:8][O:7][C:6]2[CH:5]=[CH:4][C:3]([B:12]3[O:16][C:15]([CH3:18])([CH3:17])[C:14]([CH3:20])([CH3:19])[O:13]3)=[C:2]([Cl:1])[C:11]1=2)[CH:30]=[CH2:29]

Participants

7

Reactant 4

HCID 947NitrogenHCID 7841Allyl bromideHCID 11430Potassium CarbonateHCID 595786245-chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine

Product 1

HCID 867107714-Allyl-5-chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazineYield 84.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

A solution of 5-chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (0.504 g, 1.426 mmol, Ref. WO20100130034) and K2CO3 (0.504 g, 3.65 mmol) in dry DMF (5 mL) was sparged with N2 for 5 min, then treated with allyl bromide (0.8 mL, 9.17 mmol). The reaction tube was sealed and then heated (70° C.) for 22 h, then cooled and diluted with water (50 mL) and extracted into EtOAc (50 mL). The organic layer was washed with water, brine, then dried (Na2SO4), filtered, concentrated, and purified by biotage chromatography (4 g SiO2, 0% (3 CV), 0-40% (15 CV), 40% (2 CV); EtOAc in hexanes) to afford the desired product (0.403 g, 1.201 mmol, 84% yield) as a clear viscous oil. 1H NMR (500 MHz, CDCl3) δ 7.30 (d, J=8.2 Hz, 1H), 6.79 (d, J=8.2 Hz, 1H), 6.15-6.02 (m, 1H), 5.31 (dd, J=17.2, 1.4 Hz, 1H), 5.28-5.21 (m, 1H), 4.18-4.13 (m, 2H), 3.59 (d, J=6.0 Hz, 2H), 3.14-3.07 (m, 2H), 1.36 (s, 12H). LCMS (M+H)=336.9.

Workup

  1. customThe reaction tube was sealed
  2. temperaturecooled
  3. extractionextracted into EtOAc (50 mL)
  4. washThe organic layer was washed with water, brine
  5. dry with materialdried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated
  8. custompurified by biotage chromatography (4 g SiO2, 0% (3 CV), 0-40% (15 CV), 40% (2 CV); EtOAc in hexanes)

Sources & evidence

ORD record
ord-4dc07a664aea4b5cacfab6ff8c2665d0
Source dataset
uspto-grants-2014_12
Patent number
US08906929B2

Reaction notes

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