Phosphorus oxychloride → Tert-butyl 4-[({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}amino)carbonyl]-4-phenylpiperidine-1-carboxylate

HRID 386830

Reaction equation

HRID 386830 reaction equation
[NH2:1][C:2]1[C:3]([C:7]2[N:11]([C:12]3[CH:17]=[CH:16][C:15]([F:18])=[C:14]([Br:19])[CH:13]=3)[C:10](=[O:20])[O:9][N:8]=2)=[N:4][O:5][N:6]=1.[C:21]([O:25][C:26]([N:28]1[CH2:33][CH2:32][C:31]([C:37]2[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=2)([C:34](O)=[O:35])[CH2:30][CH2:29]1)=[O:27])([CH3:24])([CH3:23])[CH3:22].P(Cl)(Cl)(Cl)=O>CN(C)C1C=CN=CC=1.C(#N)C>[Br:19][C:14]1[CH:13]=[C:12]([N:11]2[C:10](=[O:20])[O:9][N:8]=[C:7]2[C:3]2[C:2]([NH:1][C:34]([C:31]3([C:37]4[CH:38]=[CH:39][CH:40]=[CH:41][CH:42]=4)[CH2:32][CH2:33][N:28]([C:26]([O:25][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:27])[CH2:29][CH2:30]3)=[O:35])=[N:6][O:5][N:4]=2)[CH:17]=[CH:16][C:15]=1[F:18]

Participants

6

Conditions

Temperature
100 °C

Procedure

A solution of 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(3-bromo-4-fluorophenyl)-1,2,4-oxadiazol-5(4H)-one (0.15 g, 0.44 mmol), 1-(tert-butoxycarbonyl)-4-phenylpiperidine-4-carboxylic acid (0.4 g, 1.3 mmol), and 4-dimethylaminopyridine (32 mg, 0.26 mmol) in acetonitrile (2 mL) was treated with phosphoryl chloride (0.13 mL, 1.4 mmol) and heated in the microwave at 100° C. for 10 min. The reaction mixture was concentrated and the residue was diluted with ethyl acetate (25 mL) and washed with water (25 mL) and brine (25 mL), dried with sodium sulfate, filtered, and concentrated to a crude residue which was purified by silica gel to give the coupled product, tert-butyl 4-[({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}amino)carbonyl]-4-phenylpiperidine-1-carboxylate. This material was diluted with dichloromethane (5 mL) and treated with 4.0 M HCl in 1,4-dioxane (3 mL) and stirred for 45 min. The reaction mixture was concentrated and the crude residue was purified by preparative LCMS to give the desired product (10 mg, 4%). LCMS for C22H19BrFN6O4 (M+H)+: m/z=529.0, 531.0.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. additionthe residue was diluted with ethyl acetate (25 mL)
  3. washwashed with water (25 mL) and brine (25 mL)
  4. dry with materialdried with sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated to a crude residue which
  7. customwas purified by silica gel

Sources & evidence

ORD record
ord-5941d0c089d24f309032755e72a893f9
Source dataset
uspto-grants-2013_02
Patent number
US08372870B2

Linked notes

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