Methyl 4-chloroacetoacetate → 2-(4-Tetrahydrothiapyranylidene)-3-oxo-4-chlorobutyric acid, methyl ester

HRID 893570Notes

Reaction equation

HRID 893570 reaction equation
[S:1]1[CH2:6][CH2:5][CH:4](C=O)[CH2:3][CH2:2]1.[CH3:9][O:10][C:11](=[O:17])[CH2:12][C:13]([CH2:15][Cl:16])=[O:14].C(OCC)(=O)C.CCCCCC>C(OCC)(=O)C.N1CCCCC1.C(O)(=O)C>[S:1]1[CH2:6][CH2:5][C:4](=[C:12]([C:13](=[O:14])[CH2:15][Cl:16])[C:11]([O:10][CH3:9])=[O:17])[CH2:3][CH2:2]1

Participants

7

Reactant 3

HCID 36240Methyl 4-chloroacetoacetateHCID 20143720Thiane-4-carbaldehydeHCID 21226206Ethyl acetate hexane

Product 1

HCID 867459492-(4-Tetrahydrothiapyranylidene)-3-oxo-4-chlorobutyric acid, methyl ester

Reagents, catalysts & solvents 3

HCID 176Acetic AcidCatalystHCID 8082PiperidineCatalystHCID 8857Ethyl AcetateSolvent2×

Procedure

Tetrahydrothiapyran-4-carboxaldehyde (1.5g) in ethyl acetate (10 ml) was treated with methyl-4-chloroacetoacetate (1.5g), 4A sieve (3g) and the mixture cooled in an ice-bath. Piperidine (3 drops) and acetic acid (3 drops) were now added and the mixture stirred at 0-5° for 45 min. Excess ethyl acetate was added and the organic solution washed with 1M hydrochloric acid. After washing the extracts with water they were dried over anhydrous magnesium sulphate and evaporated to give a colourless oil. Chromatography o silica gel using ethyl acetate-hexane mixtures gave the title compound mixture Z/E (1:2)) as a colourless oil (2g). νmax (CHCl3) 1720 and 1630 cm-1 ; δ(CDCl3) inter alia 3.82(s) and 3.87(s), 6.84 (d, J=10Hz) and 6.94 (d, J™10Hz) m/e 262 (M+).

Workup

  1. temperaturethe mixture cooled in an ice-bath
  2. washthe organic solution washed with 1M hydrochloric acid
  3. washAfter washing the extracts with water they
  4. dry with materialwere dried over anhydrous magnesium sulphate
  5. customevaporated
  6. customto give a colourless oil

Sources & evidence

ORD record
ord-bdbec689e74346e6a01afb27e386d2d5
Source dataset
uspto-grants-1992_06
Patent number
US05126335

Reaction notes

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