Diethyl Malonate → 2H-1-Benzopyran-3-carboxylic acid, 7-(diethylamino)-2-oxo-, ethyl ester

HRID 443318Notes

Reaction equation

HRID 443318 reaction equation
[CH2:1]([N:3]([CH2:13][CH3:14])[C:4]1[CH:11]=[CH:10][C:7]([CH:8]=O)=[C:6]([OH:12])[CH:5]=1)[CH3:2].[C:15](OCC)(=[O:22])[CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18].N1CCCCC1>C(O)C>[CH2:1]([N:3]([CH2:13][CH3:14])[C:4]1[CH:5]=[C:6]2[C:7]([CH:8]=[C:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:15](=[O:22])[O:12]2)=[CH:10][CH:11]=1)[CH3:2]

Participants

5

Reactant 3

HCID 7761Diethyl MalonateHCID 8082PiperidineHCID 872934-(Diethylamino)-2-hydroxybenzaldehyde

Product 1

HCID 1200142H-1-Benzopyran-3-carboxylic acid, 7-(diethylamino)-2-oxo-, ethyl ester

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

--A solution of 4-diethylamino-2-hydroxy-benzaldehyde (29.8 g, 154 mmol) and diethyl malonate (23.8 ml, 157 mmol) in ethanol (185 ml) was treated with piperidine (1.37 ml, 13.9 mmol) and heated under reflux for 4 h. The solution was allowed to cools then concentrated under reduced pressure to approx. half-volume diluted with ether and washed with water, dilute aq. NaOH and water, dried and evaporated under reduced pressure. Trituration of the residue with EtOH (approx. 15 ml) gave yellow crystals which were recrystallised from EtOAc-light petroleum to give the ester 1 as bright yellow prisms (18 the m.p. 76-77° C. A sample recrystallised a second time had m.p. 77-78° C. (Found: C, 66.4; H, 6.7g N, 4.8. C16H9NO4 requires C, 66.4; H, 6.6; N, 4.8%). The discrepancy with the m.p. (87° C.) reported by Kendal et al. (GB 867,592), together with the sharp m.p. and satisfactory analytical result for the present sample suggests that the digits of the reported value may accidently have been transposed.

Workup

  1. temperatureheated
  2. temperatureunder reflux for 4 h
  3. concentrationthen concentrated under reduced pressure
  4. additiondiluted with ether
  5. washwashed with water, dilute aq. NaOH and water
  6. customdried
  7. customevaporated under reduced pressure
  8. customTrituration of the residue with EtOH (approx. 15 ml) gave yellow crystals which
  9. customwere recrystallised from EtOAc-light petroleum

Sources & evidence

ORD record
ord-a410396d14ec4a91aba2151f2b2245a8
Source dataset
uspto-grants-1999_04
Patent number
US05898069

Reaction notes

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