Water → 1-Benzyl 4-tert-butyl piperidine-1,4-dicarboxylate
Reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][CH:14]([C:17]([OH:19])=[O:18])[CH2:13][CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:20](O)([CH3:23])([CH3:22])[CH3:21].O.NC1C(C(ON2C3C=CC=CC=3N=N2)=O)=C2N=CC(CC#N)=CN2N=1>C(Cl)Cl.CN(C1C=CN=CC=1)C>[N:11]1([C:9]([O:8][CH2:1][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=2)=[O:10])[CH2:12][CH2:13][CH:14]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:15][CH2:16]1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
In a 5 L flange flask was charged 1-benzyloxycarbonylpiperidine-4-carboxylic acid 20 (200 g, 759.6 mmol) in DCM (500.0 mL) followed by additional DCM (2.000 L), t-butanol (140.8 g, 181.7 mL, 1.899 mol) and DMAP (46.40 g, 379.8 mmol). The mixture was cooled on ice/salt/water bath (internal −3.4° C.). 3-(ethyliminomethyleneamino)-N,N-dimethyl-propan-1-amine (Hydrochloric Acid (1)) (145.6 g, 759.6 mmol) was added portionwise over 15 mins, with addition funnel rinsed with DCM (500.0 mL). Mixture was stirred on ice bath for approx. 2 h. Ice bath was then removed (internal 3° C.) and allowed to warm to room temperature overnight. Mixture was washed with 5% citric acid (2×500 mL), then saturated NaHCO3 (500 mL), water (500 mL), and organics dried over MgSO4, which was then filtered and concentrated in vacuo to leave product 21 as a viscous light yellow oil which turned to a white solid on standing. (246.1 g, 101%). 1H NMR (500 MHz, DMSO-d6) δ 7.40-7.31 (m, 5H), 5.08 (s, 2H), 3.90 (dt, 2H), 2.93 (br s, 2H), 2.43 (tt, 1H), 1.80-1.76 (m, 2H) and 1.45-1.37 (m, 11H).
Workup
- washrinsed with DCM (500.0 mL)
- customIce bath was then removed (internal 3° C.)
- washMixture was washed with 5% citric acid (2×500 mL)
- dry with materialsaturated NaHCO3 (500 mL), water (500 mL), and organics dried over MgSO4, which
- filtrationwas then filtered
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-6b07e77b0715489fa89d5739dd258080
- Source dataset
- uspto-grants-2016_05
- Patent number
- US09340546B2
Reaction notes
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