Nitrogen → 4-[2-(4-tert-Butyl-phenyl)-benzooxazol-4-yl]-piperazine-1-carboxylic acid tert-butyl ester

HRID 491419Notes

Reaction equation

HRID 491419 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:19]=[CH:18][CH:17]=[C:16]([OH:20])[C:15]=2[N+:21]([O-])=O)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].N#N.[C:26]([C:30]1[CH:37]=[CH:36][C:33]([CH:34]=O)=[CH:32][CH:31]=1)([CH3:29])([CH3:28])[CH3:27]>[Pd].CC(O)C>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[C:15]3[N:21]=[C:34]([C:33]4[CH:36]=[CH:37][C:30]([C:26]([CH3:29])([CH3:28])[CH3:27])=[CH:31][CH:32]=4)[O:20][C:16]=3[CH:17]=[CH:18][CH:19]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 3

HCID 947NitrogenHCID 703244-tert-ButylbenzaldehydeHCID 576783021-Piperazinecarboxylic acid, 4-(3-hydroxy-2-nitrophenyl)-, 1,1-dimethylethyl ester

Product 1

HCID 576783004-[2-(4-tert-Butyl-phenyl)-benzooxazol-4-yl]-piperazine-1-carboxylic acid tert-butyl esterYield 81%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 3776IsopropanolSolvent

Conditions

Temperature
80 °C

Procedure

4-(3-hydroxy-2-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (1.00 g, 3.09 mmol) was charged to a 250 mL round bottom flask containing 10% Pd/C, stir bar and septum. Under a positive stream of N2, 2-propanol (80 mL) was added via syringe. The flask was evacuated and fitted with a balloon containing H2 and stirred, under H2, at room temperature for 18 h. LC-MS indicated only aniline present. 4-tert-Butyl-benzaldehyde (800 μL, 4.64 mmol) was added, the balloon was replaced with an air condenser and the stirring solution was heated to 80° C. for 48 h. The reaction was cooled to room temperature and filtered through celite to remove the catalyst and the solvent removed in vacuo to give a brown oil. This oil was adsorbed onto silica and purified by column chromatography, eluting with 11% ethyl acetate in hexane to afford the product as a clear waxy material (1.09 g, 81%). Mass Spectrum (+ESI): 436 [M+H]+.

Workup

  1. customThe flask was evacuated
  2. customfitted with a balloon
  3. additioncontaining H2
  4. stirringstirred, under H2, at room temperature for 18 h
  5. customthe balloon was replaced with an air condenser
  6. temperatureThe reaction was cooled to room temperature
  7. filtrationfiltered through celite
  8. customto remove the catalyst
  9. customthe solvent removed in vacuo
  10. customto give a brown oil
  11. custompurified by column chromatography
  12. washeluting with 11% ethyl acetate in hexane

Sources & evidence

ORD record
ord-bb94b1840edc4743a4f687e182c14afa
Source dataset
uspto-grants-2009_05
Patent number
US07531542B2

Reaction notes

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