Triphenylphosphine → ethyl 1-{2-[(tert-butoxycarbonyl)amino]propyl}-3-(phenoxymethyl)-1H-pyrazole-5-carboxylate

HRID 1773775Notes

Reaction equation

N(C(OC(C)(C)C)=O)=NC(OC(C)(C)C)=O.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[C:36]([O:40][C:41](=[O:47])[NH:42][CH:43]([CH3:46])[CH2:44]O)([CH3:39])([CH3:38])[CH3:37].[CH2:48]([O:50][C:51]([C:53]1[NH:54][N:55]=[C:56]([CH2:58][O:59][C:60]2[CH:65]=[CH:64][CH:63]=[CH:62][CH:61]=2)[CH:57]=1)=[O:52])[CH3:49]>C1COCC1>[CH2:48]([O:50][C:51]([C:53]1[N:54]([CH2:44][CH:43]([NH:42][C:41]([O:40][C:36]([CH3:39])([CH3:38])[CH3:37])=[O:47])[CH3:46])[N:55]=[C:56]([CH2:58][O:59][C:60]2[CH:65]=[CH:64][CH:63]=[CH:62][CH:61]=2)[CH:57]=1)=[O:52])[CH3:49]

Participants

Conditions

Temperature: 120 °C

Procedure

Di-tert-butyl azodicarboxylate (2.52 g, 10.96 mmol) was added to a stirred solution of triphenylphosphine (2.87 g, 10.96 mmol), 2-hydroxy-rac-1-methyl-ethyl-carbamic acid tert-butyl ester (2.13 g, 12.18 mmol) and 5-phenoxymethyl-2H-pyrazole-3-carboxylic acid ethyl ester (1.5 g, 6.09 mmol) in THF (45 mL). The mixture was stirred at 120° C. for 20 minutes under microwave irradiation and the solvents evaporated in vacuo. The crude product was purified by open column chromatography (silica; AcOEt in DCM 0/100 to 10/90). The desired fractions were collected and the solvents evaporated in vacuo to yield rac-2-(2-tert-butoxycarbonylamino-propyl)-5-phenoxymethyl-2H-pyrazole-3-carboxylic acid ethyl ester (5.58 g, 91% yield, 40% pure) as a colorless oil that crystallized upon standing in white crystals.

Workup

customthe solvents evaporated in vacuo
customThe crude product was purified by open column chromatography (silica; AcOEt in DCM 0/100 to 10/90)
customThe desired fractions were collected
customthe solvents evaporated in vacuo

Sources & evidence

ORD record: ord-bdf7478d13254b61adf49c632cfb1c24
Source dataset: uspto-grants-2016_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09255103B2

Reaction notes

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