4-Amino-1-Boc-piperidine → tert-Butyl 4-((5-nitrobenzo[d]oxazol-2-yl)amino)piperidine-1-carboxylate

HRID 1990883Notes

Reaction equation

CS[C:3]1[O:4][C:5]2[CH:11]=[CH:10][C:9]([N+:12]([O-:14])=[O:13])=[CH:8][C:6]=2[N:7]=1.[C:15]([O:19][C:20]([N:22]1[CH2:27][CH2:26][CH:25]([NH2:28])[CH2:24][CH2:23]1)=[O:21])([CH3:18])([CH3:17])[CH3:16]>CC(N(C)C)=O>[C:15]([O:19][C:20]([N:22]1[CH2:27][CH2:26][CH:25]([NH:28][C:3]2[O:4][C:5]3[CH:11]=[CH:10][C:9]([N+:12]([O-:14])=[O:13])=[CH:8][C:6]=3[N:7]=2)[CH2:24][CH2:23]1)=[O:21])([CH3:18])([CH3:16])[CH3:17]

Participants

Conditions

Temperature: 140 °C

Procedure

A mixture of 2-methylsulfanyl-5-nitro-benzooxazole (10.0 g, 47.57 mmol, 1.0 equiv) and 4-amino-piperidine-1-carboxylic acid tert-butyl ester (14.29 g, 71.36 mmol, 1.5 equiv) in anhydrous DMAc (50 mL) was heated to 140° C. for 72 h. The solution was concentrated by evaporation under reduced pressure and the crude reaction product purified with column chromatography on silica eluting with ethyl acetate/cyclohexane (1:1) to give 4.1 g (24%) of the title compound. 1H NMR (300 MHz, CDCl3): δ 1.48 (s, 9H), 1.50-1.53 (m, 2H), 2.11-2.20 (m, 2H), 2.87-3.05 (m, 2H), 3.89-4.01 (m, 1H), 4.05-4.16 (m, 2H), 5.51 (d, J=7.5 Hz, 1H), 7.30 (d, J=8.7 Hz, 1H), 8.02 (dd, J=8.7 Hz, J=2.3 Hz, 1H), 8.18 (d, J=2.3 Hz, 1H). 13C NMR (75 MHz, CDCl3): δ 28.40, 32.29, 42.46, 50.88, 79.81, 108.36, 111.99, 116.77, 143.90, 145.23, 152.38, 154.66, 162.69. MS (ISP): 363.5 [M+H]+.

Workup

concentrationThe solution was concentrated by evaporation under reduced pressure
customthe crude reaction product
custompurified with column chromatography on silica eluting with ethyl acetate/cyclohexane (1:1)

Sources & evidence

ORD record: ord-2310756b97dc4834824c09dffdb3e256
Source dataset: uspto-grants-2010_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07645753B2

Reaction notes

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