Tetrahydrofuran → 8-Chloro-5,6-dihydro-4-oxo-6-phenyl-4H-pyrazolo[1,5-a][1,4]benzodiazepine-2-carboxaldehyde

HRID 236724

Reaction equation

HRID 236724 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]3[N:12]=[C:13]([CH2:15][OH:16])[CH:14]=[C:10]3[C:9](=[O:17])[NH:8][CH:7]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)[C:6]=2[CH:24]=1.C1COCC1>O=[Mn]=O.C1COCC1.CCCCCC>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]3[N:12]=[C:13]([CH:15]=[O:16])[CH:14]=[C:10]3[C:9](=[O:17])[NH:8][CH:7]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)[C:6]=2[CH:24]=1

Participants

5

Reactant 2

HCID 8028TetrahydrofuranHCID 123778908-Chloro-5,6-dihydro-4-oxo-6-phenyl-4H-pyrazolo[1,5-a][1,4]benzodiazepine-2-methanol

Product 1

HCID 123778918-Chloro-5,6-dihydro-4-oxo-6-phenyl-4H-pyrazolo[1,5-a][1,4]benzodiazepine-2-carboxaldehyde

Reagents, catalysts & solvents 2

HCID 14801Manganese dioxideCatalystHCID 21883165Tetrahydrofuran hexaneSolvent

Procedure

A solution of 5.85 g. (17 mmol) of the end product of Example 14 in 600 ml. dry THF was mixed with 24 g. of activated MnO2 and heated to reflux for 17 hours. The mixture was cooled, filtered and the collected solids washed thoroughly with THF. The combined filtrate and washings were concentrated in vacuo. Recrystallization of this crude product from THF/hexane yielded the desired end product. An analytical sample was prepared by an additional recrystallization from THF/hexane and was obtained as colorless plates: mp 276°-278°.

Workup

  1. temperatureto reflux for 17 hours
  2. temperatureThe mixture was cooled
  3. filtrationfiltered
  4. washthe collected solids washed thoroughly with THF
  5. concentrationThe combined filtrate and washings were concentrated in vacuo
  6. customRecrystallization of this crude product from THF/hexane
  7. customyielded the desired end product
  8. customwas obtained as colorless plates

Sources & evidence

ORD record
ord-128393ab42a447bb8a2e9052fecc403d
Source dataset
uspto-grants-1979_06
Patent number
US04157331

Linked notes

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