Hydrochloric Acid → 1-[2-(Benzofurazan-5-yl)ethyl]-4-piperidinone

HRID 1781407Notes

Reaction equation

HRID 1781407 reaction equation
[N:1]1[O:5][N:4]=[C:3]2[CH:6]=[C:7]([CH2:10][CH2:11][N:12]3[CH2:21][CH2:20][C:15]4(OCC[O:16]4)[CH2:14][CH2:13]3)[CH:8]=[CH:9][C:2]=12.Cl.[OH-].[Na+]>>[N:1]1[O:5][N:4]=[C:3]2[CH:6]=[C:7]([CH2:10][CH2:11][N:12]3[CH2:21][CH2:20][C:15](=[O:16])[CH2:14][CH2:13]3)[CH:8]=[CH:9][C:2]=12

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 190452468-[2-(Benzofurazan-5-yl)ethyl]1,4-dioxa-8-aza spiro[4.5]decane

Product 1

HCID 190452521-[2-(Benzofurazan-5-yl)ethyl]-4-piperidinoneYield 88%

Procedure

A solution of 8-[2-(benzofurazan-5-yl)ethyl]1,4-dioxa-8-aza spiro[4.5]decane (20.0 g, 69.1 mmol) in 1N aqueous HCl (200 mL, 200 mmol) was heated to reflux for 1.5 hr. The cooled solution was adjusted to pH 8.5 with 40% aqueous sodium hydroxide and extracted with ethyl acetate (250 mL then 100 mL). The combined extracts were washed twice with 1N aqueous HCl (200 mL combined). The acid layers were heated to reflux for 1 hr and then cooled. Basification as above, extraction into ethyl acetate, drying (Na2SO4), concentration, and trituration with hexanes afforded 1-[2-(benzofurazan-5-yl)ethyl]piperidin-4-one as a solid 14.9 g (88%). HPLC: Rt=3.0 min, 90:10 (0.1% H3PO4 in water: acetonitrile) flow=2.0 mL/min, Waters C18 micro bondapak 25 cmL.

Workup

  1. temperatureto reflux for 1.5 hr
  2. extractionextracted with ethyl acetate (250 mL
  3. washThe combined extracts were washed twice with 1N aqueous HCl (200 mL combined)
  4. temperatureThe acid layers were heated
  5. temperatureto reflux for 1 hr
  6. temperaturecooled
  7. extractionBasification as above, extraction into ethyl acetate
  8. customdrying
  9. concentration(Na2SO4), concentration, and trituration with hexanes

Sources & evidence

ORD record
ord-533ba5fdbb8c431592ef5123fe96aa69
Source dataset
uspto-grants-1997_05
Patent number
US05633247

Reaction notes

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