Tributylphosphine → HCID 69546165, compound

HRID 1794556Notes

Reaction equation

HRID 1794556 reaction equation
C(OC(N=NC(OC(C)C)=O)=O)(C)C.[CH2:15]([O:17][C:18]([C:20]1[S:21][C:22]([C:27]([O:29][CH2:30][CH3:31])=[O:28])=[C:23]([OH:26])[C:24]=1[OH:25])=[O:19])[CH3:16].[F:32][C:33]([F:38])([CH2:36]O)[CH2:34]O.C(P(CCCC)CCCC)CCC>O1CCCC1>[CH2:30]([O:29][C:27]([C:22]1[S:21][C:20]([C:18]([O:17][CH2:15][CH3:16])=[O:19])=[C:24]2[C:23]=1[O:26][CH2:36][C:33]([F:38])([F:32])[CH2:34][O:25]2)=[O:28])[CH3:31]

Participants

6

Reactant 4

HCID 13831TributylphosphineHCID 75555Diisopropyl diazene-1,2-dicarboxylate2×HCID 957442,2-Difluoropropane-1,3-diolHCID 2455033,4-Dihydroxy-thiophene-2,5-dicarboxylic acid diethyl ester

Product 1

HCID 69546165HCID 69546165, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
100 °C

Procedure

3,3-Difluoro-3,4-dihydro-2H-thieno[3,4-b][1,4]-dioxepine-6,8-dicarboxylic acid diethyl ester was synthesized by adding dropwise 3.4 mL (17.2 mmol) of azodicarboxylic acid diisopropyl ester (ADC) to a mixture of 1.77 g (6.67 mmol) of 3,4-dihydroxythiophen-2,5-dicarboxylic acid diethyl ester, 748 mg of 2,2-difluoro-1,3-propanediol and 4.3 mL of tributylphosphine in 12 mL of absolute tetrahydrofuran under argon at 20° C. with ice-cooling. After completion of the addition of ADC the resulting mixture was allowed to stand at room temperature for 4 days. The tetrahydrofuran was then distilled off and the residue heated for 12.5 hours at 100° C. after which it was dissolved in ethyl acetate. The ethyl acetate solution was washed three times with saturated sodium bicarbonate solution, then with deionized water, dried with anhydrous magnesium sulphate, concentrated and the residue chromatographically purified on a kieselgel 60 column with heptane/ethyl acetate as eluant. 335 mg (corresponding to a yield of 15%) of the desired product was obtained with a melting point of 121–122° C., as characterized by:

Workup

  1. custom3,3-Difluoro-3,4-dihydro-2H-thieno[3,4-b][1,4]-dioxepine-6,8-dicarboxylic acid diethyl ester was synthesized
  2. temperaturecooling
  3. distillationThe tetrahydrofuran was then distilled off
  4. dissolutionwas dissolved in ethyl acetate
  5. washThe ethyl acetate solution was washed three times with saturated sodium bicarbonate solution
  6. dry with materialwith deionized water, dried with anhydrous magnesium sulphate
  7. concentrationconcentrated
  8. customthe residue chromatographically purified on a kieselgel 60 column with heptane/ethyl acetate as eluant

Sources & evidence

ORD record
ord-919f8f5fbfa64bd7b3507f868f406aaf
Source dataset
uspto-grants-2006_04
Patent number
US07022811B2

Reaction notes

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