Hydrochloric Acid → 2-Chloro-8-(1-hydroxaminoethyl)phenoxathiin

HRID 1087383Notes

Reaction equation

HRID 1087383 reaction equation
[Cl:1][C:2]1[CH:15]=[CH:14][C:13]2[O:12][C:11]3[C:6](=[CH:7][C:8]([C:16](=[N:18][OH:19])[CH3:17])=[CH:9][CH:10]=3)[S:5][C:4]=2[CH:3]=1.B.N1C=CC=CC=1.Cl>C(O)C.C1COCC1>[Cl:1][C:2]1[CH:15]=[CH:14][C:13]2[O:12][C:11]3[C:6](=[CH:7][C:8]([CH:16]([NH:18][OH:19])[CH3:17])=[CH:9][CH:10]=3)[S:5][C:4]=2[CH:3]=1

Participants

6

Reactant 3

HCID 313Hydrochloric Acid2×HCID 2723995Borane;pyridine2×HCID 86744936HCID 86744936, compound

Product 1

HCID 867449352-Chloro-8-(1-hydroxaminoethyl)phenoxathiinYield 80.4%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a suspension of 2-chloro-8-(1-hydroximinoethyl)phenoxathiin (C.A. 66, 2519a, 1967) (425 mg, 1.456 mmol) in ethanol (12 mL) and THF (5 mL) at room temperature there was added pyridine-borane (271 mg, 0.3 mL, 2.92 mmol) and 4M ethanolic HCl (1.1 mL, 4.4 mmole); the mixture was stirred at room temperature overnight, there was added more pyridine-borane (0.35 mL) and 4M ethanolic HCl (2 mL) and stirring was continued for 2 hours. The solvents were evaporated, the residue diluted with water and ethyl acetate and basified with 1N aqueous NaOH. From the organic phase a crude product was obtained which was chromatographed on silica gel, eluting with a 1:1 mixture of ethyl acetate-hexane, to afford the title product (344 mg) as a white solid, m.p.: 103°-105° C.

Workup

  1. stirringstirring
  2. waitwas continued for 2 hours
  3. customThe solvents were evaporated
  4. additionthe residue diluted with water and ethyl acetate
  5. customFrom the organic phase a crude product was obtained which
  6. customwas chromatographed on silica gel
  7. washeluting with a 1:1 mixture of ethyl acetate-hexane

Sources & evidence

ORD record
ord-92ea4e523a3142229d1dfba4788ad5da
Source dataset
uspto-grants-1991_07
Patent number
US05036067

Reaction notes

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