Diethyl Ether → Ethyl 2-n-propylpyridine-3-carboxylate

HRID 1422107Notes

Reaction equation

[CH:1]([CH:3]=[CH2:4])=O.[NH2:5][C:6]([CH2:13][CH2:14][CH3:15])=[CH:7][C:8]([O:10][CH2:11][CH3:12])=[O:9].[S].C(OCC)C>N1CCCCC1.C(O)C.O>[CH2:13]([C:6]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:4][CH:3]=[CH:1][N:5]=1)[CH2:14][CH3:15]

Participants

Conditions

Temperature: 100 °C

Procedure

Acrolein (30 g, 0.52 mmol) was added during a period of 2 hours to a stirred solution of ethyl 3-amino-hex-2-enoate (62 g, 0.4 mmol) dissolved in 2 g of piperidine and 300 ml of anhydrous ethanol. The mixture was refluxed for 3 hours and the ethanol was evaporated. The remaining oil was heated to 100° C. and solid sulfur (52 g, 1.6 mmol) was carefully added in portions. The temperature was elevated to 150° C. for 3 hours. The mixture was cooled to room temperature and 200 ml of diethyl ether and 800 ml of water was added. The organic material was extracted into diethyl ether (2×200 ml). The combined organic layer were dried overmagnesium sulfate, and evaporated to an oil. The crude product was purified by column chromatography over silica gel 60, using diethyl ether as the eluent to afford 50 g (65%) of ethyl 2-n-propylpyridine-3-carboxylate as an oil. 1H--NMR (CDCl3, 200 MHz) δ: 1.01 (t, 3 H); 1.40 (t, 3 H); 1.75 (sextet, 2 H); 3.12 (t, 2 H); 4.38 (q, 2 H); 7.19 (dd, 1 H); 8.13 (dd, 1 H); 8.63 (dd, 1 H).

Workup

temperatureThe mixture was refluxed for 3 hours
customthe ethanol was evaporated
temperatureThe mixture was cooled to room temperature
extractionThe organic material was extracted into diethyl ether (2×200 ml)
dry with materialThe combined organic layer were dried overmagnesium sulfate
customevaporated to an oil
customThe crude product was purified by column chromatography over silica gel 60

Sources & evidence

ORD record: ord-056938b2df49485aadfd43753c01bdb2
Source dataset: uspto-grants-2000_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06080754

Reaction notes

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