Methyl acetoacetate → 4-[1-(Cyclohexylmethyl-amino)-ethylidene]-pent-2-enedioic acid dimethyl ester

HRID 919927Notes

Reaction equation

HRID 919927 reaction equation
[CH:1]1([CH2:7][NH2:8])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[CH3:9][O:10][C:11](=[O:16])[CH2:12][C:13](=O)[CH3:14].[CH3:17][O:18][C:19](=[O:22])[C:20]#[CH:21]>CO>[CH3:17][O:18][C:19](=[O:22])[CH:20]=[CH:21][C:12](=[C:13]([NH:8][CH2:7][CH:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1)[CH3:14])[C:11]([O:10][CH3:9])=[O:16]

Participants

5

Reactant 3

HCID 7757Methyl acetoacetateHCID 13536Methyl propiolateHCID 76688Cyclohexanemethylamine

Product 1

HCID 867141524-[1-(Cyclohexylmethyl-amino)-ethylidene]-pent-2-enedioic acid dimethyl esterYield 80.5%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of cyclohexanemethylamine (3 g, 26.5 mmol) and 3-oxo-butyric acid methyl ester (3.5 mL, 31.8 mmol) in MeOH (100 mL) was refluxed for 2 h. Propynoic acid methyl ester (3.6 mL, 39.8 mmol) was added, and the resulting mixture was refluxed for 2 days. After cooling to r.t., the solvent was evaporated, and the crude oil was recrystallized from MeOH to give 6.3 g of the title compound as a light tan solid. 1H NMR (CDCl3, 200 MHz): δ=10.73 (br s, 1H), 7.76 (d, 1H, J=15.4 Hz), 6.06 (d, 1H, J=15.4 Hz), 3.77 (s, 3H), 3.72 (s, 3H), 3.18 (t, 2H, J=6.2 Hz), 2.25 (s, 3H), 0.80-1.90 (m, 11H).

Workup

  1. temperaturewas refluxed for 2 h
  2. temperaturethe resulting mixture was refluxed for 2 days
  3. customthe solvent was evaporated
  4. customthe crude oil was recrystallized from MeOH

Sources & evidence

ORD record
ord-cf6f143389934f3f85cc90a4f88f32a2
Source dataset
uspto-grants-2016_03
Patent number
US09271970B2

Reaction notes

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