4-Aminopyridine → Methyl 2-(pyridin-4-ylamino)benzoxazole-4-carboxylate

HRID 249841Notes

Reaction equation

HRID 249841 reaction equation
Cl[C:2]1[O:3][C:4]2[C:5](=[C:7]([C:11]([O:13][CH3:14])=[O:12])[CH:8]=[CH:9][CH:10]=2)[N:6]=1.[NH2:15][C:16]1[CH:21]=[CH:20][N:19]=[CH:18][CH:17]=1.C1(P(C2CCCCC2)C2C=CC=CC=2C2C(C(C)C)=CC(C(C)C)=CC=2C(C)C)CCCCC1.C([O-])([O-])=O.[K+].[K+]>C([O-])(=O)C.[Pd+2].C([O-])(=O)C.CC(O)(C)C>[N:19]1[CH:20]=[CH:21][C:16]([NH:15][C:2]2[O:3][C:4]3[C:5](=[C:7]([C:11]([O:13][CH3:14])=[O:12])[CH:8]=[CH:9][CH:10]=3)[N:6]=2)=[CH:17][CH:18]=1

Participants

7

Reactant 4

HCID 17274-AminopyridineHCID 11430Potassium CarbonateHCID 111557942-Dicyclohexylphosphino-2',4',6'-triisoprophylbiphenylHCID 56924368Methyl 2-chlorobenzo[d]oxazole-4-carboxylate

Product 1

HCID 66873583Methyl 2-(pyridin-4-ylamino)benzoxazole-4-carboxylate

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 6386tert-ButanolSolvent

Conditions

Temperature
90 °C

Procedure

A mixture of methyl 2-chlorobenzoxazole-4-carboxylate (350 mg, 1.65 mmol), 4-aminopyridine (233 mg, 2.48 mmol), palladium(II) acetate (7.4 mg, 0.033 mmol), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (39 mg, 0.083 mmol), K2CO3 (570 mg, 4.13 mmol) and t-BuOH (4 mL) was heated to 90° C. for 40 min. After cooling to room temperature, the reaction mixture was filtered through diatomaceous earth and concentrated. The crude product was purified by column chromatography (silica gel, 9:1 CH2Cl2/CH3OH) to afford methyl 2-(pyridin-4-ylamino)benzoxazole-4-carboxylate. 1H NMR and MS consistent.

Workup

  1. temperatureAfter cooling to room temperature
  2. filtrationthe reaction mixture was filtered through diatomaceous earth
  3. concentrationconcentrated
  4. customThe crude product was purified by column chromatography (silica gel, 9:1 CH2Cl2/CH3OH)

Sources & evidence

ORD record
ord-64aad37a3af54c31889d64be9c5b2f5a
Source dataset
uspto-grants-2011_01
Patent number
US07863271B2

Reaction notes

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