Thionyl Chloride → 5-Chloro-N-hydroxy-N-(1-methylethyl)-3-(trimethylsilyl)-2-thiophenecarboxamide

HRID 376724Notes

Reaction equation

HRID 376724 reaction equation
[Cl:1][C:2]1[S:6][C:5]([C:7]([OH:9])=[O:8])=[C:4]([Si:10]([CH3:13])([CH3:12])[CH3:11])[CH:3]=1.S(Cl)([Cl:16])=O.Cl.[CH:19]([NH:22][OH:23])([CH3:21])[CH3:20].C([O-])(O)=O.[Na+]>C(Cl)Cl.O>[Cl:1][C:2]1[S:6][C:5]([C:7]([Cl:16])=[O:8])=[C:4]([Si:10]([CH3:13])([CH3:12])[CH3:11])[CH:3]=1.[Cl:1][C:2]1[S:6][C:5]([C:7]([N:22]([OH:23])[CH:19]([CH3:21])[CH3:20])=[O:9])=[C:4]([Si:10]([CH3:13])([CH3:12])[CH3:11])[CH:3]=1

Participants

8

Reactant 4

HCID 24386Thionyl ChlorideHCID 170873N-Isopropylhydroxylamine HydrochlorideHCID 516892Sodium BicarbonateHCID 186302395-Chloro-3-(trimethylsilyl)-2-thiophenecarboxylic acid

Product 2

HCID 120399765-Chloro-N-hydroxy-N-(1-methylethyl)-3-(trimethylsilyl)-2-thiophenecarboxamideHCID 540248365-Chloro-3-(trimethylsilyl)-2-thiophenecarboxylic acid chloride

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent2×

Procedure

5-Chloro-3-(trimethylsilyl)-2-thiophenecarboxylic acid chloride was prepared by the reaction of 1 g 5-chloro-3-(trimethylsilyl)-2-thiophenecarboxylic acid (prepared as in Example 263) and 6 mL thionyl chloride, using the procedure of step a in Example 248. This product was dissolved in CH2Cl2 at 0° C. and added to a mixture of N-isopropylhydroxylamine hydrochloride (0.55 g, 5 mmol) and 4 g NaHCO3 in 20 mL CH2Cl2 and 20 mL water. The resulting reaction mixture was stirred at RT for additional 3 h. The organic layer was separated, washed with brine, dried and concentrated. The residue was purified by flash chromatography with 8% ethyl acetate/hexane to give 80 mg of the title compound. m.p. 146°-150° C.

Workup

  1. customThe resulting reaction mixture
  2. customThe organic layer was separated
  3. washwashed with brine
  4. customdried
  5. concentrationconcentrated
  6. customThe residue was purified by flash chromatography with 8% ethyl acetate/hexane

Sources & evidence

ORD record
ord-8f782da47168496ebb2490d8b5fec697
Source dataset
uspto-grants-2000_02
Patent number
USRE036562

Reaction notes

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