Water → 5,6-Dihydro-4-oxo-5-(2-ethoxycarbonylethyl)thieno[2,3-b]thiopyran

HRID 2254310Notes

Reaction equation

HRID 2254310 reaction equation
S(Cl)(Cl)=O.[S:5]1[CH:9]=[CH:8][CH:7]=[C:6]1[S:10][CH2:11][CH:12]([CH2:16][CH2:17][C:18]([O:20][CH2:21][CH3:22])=[O:19])[C:13]([OH:15])=O.Cl[Sn](Cl)(Cl)Cl.O>CN(C=O)C.C(Cl)Cl>[O:15]=[C:13]1[CH:12]([CH2:16][CH2:17][C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH2:11][S:10][C:6]2[S:5][CH:9]=[CH:8][C:7]1=2

Participants

7

Reactant 4

HCID 962WaterHCID 24287Tin tetrachlorideHCID 24386Thionyl ChlorideHCID 19745039HCID 19745039, compound

Product 1

HCID 678831665,6-Dihydro-4-oxo-5-(2-ethoxycarbonylethyl)thieno[2,3-b]thiopyranYield 97.1%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Procedure

Under N2, thionyl chloride (5.5 g, 0.043 mol) was added dropwise to a solution of 1 (11.5 g, 0.04 mol) in DMF (4 drops) and methylene chloride (100 ml). After the addition, the solution was stirred at room temperature for 4.5 hours. The mixture was then cooled to -10° and SnCl4 (5.3 g, 0.02 mol) was added dropwise. After the addition the reaction was allowed to stir at room temperature for 28 hours. The mixture was then added to H2O and the aqueous layer extracted with EtOAc (3×). The organic extracts were backwashed with saturated NaHCO3, dried, filtered and concentrated to dryness to yield 10.5 g (97%) of 2 wherein R1, R2, R3 and R4 are each H.

Workup

  1. additionAfter the addition
  2. temperatureThe mixture was then cooled to -10°
  3. additionAfter the addition the reaction
  4. stirringto stir at room temperature for 28 hours
  5. extractionthe aqueous layer extracted with EtOAc (3×)
  6. customdried
  7. filtrationfiltered
  8. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-bd2fb372f93746fea05d5cdb04a35fba
Source dataset
uspto-grants-1993_08
Patent number
US05235059

Reaction notes

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