Dimethylformamide dimethyl acetal → tert-butyl 3-[(dimethylamino)methylene]-4-oxotetrahydro-1(2H)-pyridinecarboxylate

HRID 1713106Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11](=[O:14])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].CO[CH:17](OC)[N:18]([CH3:20])[CH3:19]>CN(C=O)C>[C:1]([O:5][C:6]([N:8]1[CH2:9][CH2:10][C:11](=[O:14])[C:12](=[CH:17][N:18]([CH3:20])[CH3:19])[CH2:13]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

Conditions

Temperature: 90 °C

Procedure

tert-Butyl-4-oxo-1-piperidinecarboxylate (10 g, 50 mmol) and N,N-dimethylformamide dimethyl acetal (7.3 ml, 55 mmol) are added to dry DMF (75 ml) under nitrogen and the mixture is heated at 90° C. for 16 hr. The reaction mixture is concentrated under reduced pressure, and the residue is partitioned between EtOAc (200 ml) and brine (200 ml). Layers are separated and the aqueous phase is extracted with EtOAc (200 ml). The combined organic extracts are dried over sodium sulfate and concentrated under reduced pressure to give a brown oil that solidifies on standing. The material is used for the next step reaction without further purification. 1H NMR (300 MHz, CDCl3) δ 7.44 (1H, s), 4.54 (2H, s), 3.59 (2H, t), 3.06 (6H, s), 2.42 (2H, t), 1.44 (9H, s); MS (+VE) m/z 255.1 (M++1).

Workup

concentrationThe reaction mixture is concentrated under reduced pressure
customthe residue is partitioned between EtOAc (200 ml) and brine (200 ml)
customLayers are separated
extractionthe aqueous phase is extracted with EtOAc (200 ml)
dry with materialThe combined organic extracts are dried over sodium sulfate
concentrationconcentrated under reduced pressure
customto give a brown oil that
customThe material is used for the next step reaction without further purification

Sources & evidence

ORD record: ord-d0eae016c7af4bbfb324e4146a9c4d30
Source dataset: uspto-grants-2010_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07795262B2

Reaction notes

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