Potassium Carbonate → tert-Butyl 2-nitro-4-(thiophen-2-yl)phenylcarbamate

HRID 62665Notes

Reaction equation

HRID 62665 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([NH:8][C:9](=[O:15])[O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[C:4]([N+:16]([O-:18])=[O:17])[CH:3]=1.[S:19]1[CH:23]=[CH:22][CH:21]=[C:20]1B(O)O.C(=O)([O-])[O-].[K+].[K+].C1(C)C=CC=CC=1P(C1C=CC=CC=1C)C1C=CC=CC=1C>COCCOC.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[N+:16]([C:4]1[CH:3]=[C:2]([C:20]2[S:19][CH:23]=[CH:22][CH:21]=2)[CH:7]=[CH:6][C:5]=1[NH:8][C:9](=[O:15])[O:10][C:11]([CH3:14])([CH3:13])[CH3:12])([O-:18])=[O:17]

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 80271Tri-o-tolylphosphineHCID 27339602-Thiopheneboronic acidHCID 52904808tert-Butyl (4-bromo-2-nitrophenyl)carbamate

Product 1

HCID 59736984tert-Butyl 2-nitro-4-(thiophen-2-yl)phenylcarbamateYield 73%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 18180031Water 1,2-dimethoxyethaneSolvent

Conditions

Temperature
90 °C

Procedure

A mixture of tert-butyl (4-bromo-2-nitrophenyl)carbamate (6.0 g, 18.92 mmol, 1.0 eq.), thiophen-2-ylboronic acid (3.2 g, 24.6 mmol, 1.3 eq.), potassium carbonate (7.84 g, 56.8 mmol, 3.0 eq.) and tetrakis(triphenylphosphine)palladium(0) (1.53 g, 1.32 mmol, 0.07 eq.), tri-tolylphosphine in DME/H2O (105 mL) was first degassed then heated to 90° C. for 20 h. The reaction was then filtered through Celite. The product was extracted with ethyl acetate. The combined organic layers were washed with water and brine, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by flash column chromatography (silica gel, 2% EtOAc/hexanes) to obtain pure tert-butyl (2-nitro-4-(thiophen-2-yl)phenyl)carbamate (4.42 g, 73% yield).

Workup

  1. customwas first degassed
  2. filtrationThe reaction was then filtered through Celite
  3. extractionThe product was extracted with ethyl acetate
  4. washThe combined organic layers were washed with water and brine
  5. dry with materialdried over anhydrous Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe crude product was purified by flash column chromatography (silica gel, 2% EtOAc/hexanes)

Sources & evidence

ORD record
ord-178d9db47d9a475eb399a78fb53ec9fe
Source dataset
uspto-grants-2016_09
Patent number
US09447030B2

Reaction notes

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