Tert-butyl 8-bromo-2-methyl-6-(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4'-piperidine]-1'-carboxylate → Tert-butyl 8-cyano-2-methyl-6-(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4'-piperidine]-1'-carboxylate
Reaction equation
Br[C:2]1[CH:3]=[C:4]([C:24]([F:27])([F:26])[F:25])[N:5]2[CH2:22][CH2:21][N:20]([CH3:23])[C:7]3([CH2:12][CH2:11][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:9][CH2:8]3)[C:6]=12.[C:28]([Zn]C#N)#[N:29]>CN(C=O)C.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[C:28]([C:2]1[CH:3]=[C:4]([C:24]([F:26])([F:25])[F:27])[N:5]2[CH2:22][CH2:21][N:20]([CH3:23])[C:7]3([CH2:8][CH2:9][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:11][CH2:12]3)[C:6]=12)#[N:29]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 150 °C
Procedure
A mixture of tert-butyl 8-bromo-2-methyl-6-(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-1′-carboxylate (1.67 g, 3.7 mmol) and dicyanozinc (234.9 μL, 3.7 mmol) in DMF (10 mL) was purged with N2 for 5 min. Pd(PPh3)4 (427.6 mg, 0.37 mmol) was added. The mixture was heated in a sealed microwave vial at 150° C. overnight. The mixture was partitioned between ethyl acetate and water. The layers were separated. The aqueous layer was extracted with ethyl acetate (3×). All organic layers were combined, washed with water (3×), brine, dried over MgSO4, filtered and concentrated to dryness. The crude material was purified by column chromatography (10-20% EtOAc/hexanes) to provide tert-butyl 8-cyano-2-methyl-6-(trifluoromethyl)spiro[3,4-dihydropyrrolo[1,2-a]pyrazine-1,4′-piperidine]-1′-carboxylate (510 mg, 35%) as a white solid. ESI-MS m/z calc. 398.2, found 399.3 (M+1)+; Retention time: 1.56 minutes (3 minute run).
Workup
- customwas purged with N2 for 5 min
- customThe mixture was partitioned between ethyl acetate and water
- customThe layers were separated
- extractionThe aqueous layer was extracted with ethyl acetate (3×)
- washwashed with water (3×), brine
- dry with materialdried over MgSO4
- filtrationfiltered
- concentrationconcentrated to dryness
- customThe crude material was purified by column chromatography (10-20% EtOAc/hexanes)
Sources & evidence
- ORD record
- ord-872a348dc8fc4cf8ae2a4a53969cdefe
- Source dataset
- uspto-grants-2014_12
- Patent number
- US08916565B2
Reaction notes
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