Potassium tert-butoxide → 3-Methoxy-8-(2,4,6-trimethyl-phenyl)-tetrahydro-pyrazolo[1,2-a][1,2,5]triazepine-7,9-dione

HRID 924602Notes

Reaction equation

HRID 924602 reaction equation
C([O:3][C:4]([N:6]1[CH2:12][CH2:11][N:10]([O:13][CH3:14])[CH2:9][CH2:8][N:7]1[C:15](=[O:26])[CH2:16][C:17]1[C:22]([CH3:23])=[CH:21][C:20]([CH3:24])=[CH:19][C:18]=1[CH3:25])=O)C.CC(C)([O-])C.[K+]>CN(C)C=O>[CH3:14][O:13][N:10]1[CH2:9][CH2:8][N:7]2[C:15](=[O:26])[CH:16]([C:17]3[C:22]([CH3:23])=[CH:21][C:20]([CH3:24])=[CH:19][C:18]=3[CH3:25])[C:4](=[O:3])[N:6]2[CH2:12][CH2:11]1

Participants

4

Reactant 2

HCID 23665647Potassium tert-butoxideHCID 867199175-Methoxy-2-[2-(2,4,6-trimethyl-phenyl)-acetyl]-[1,2,5]triazepane-1-carboxylic acid ethyl ester

Product 1

HCID 867199153-Methoxy-8-(2,4,6-trimethyl-phenyl)-tetrahydro-pyrazolo[1,2-a][1,2,5]triazepine-7,9-dioneYield 12.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 5-methoxy-2-[2-(2,4,6-trimethyl-phenyl)-acetyl]-[1,2,5]triazepane-1-carboxylic acid ethyl ester (1.035 g, 2.85 mmol) in absolute dimethylformamide (12 ml) at room temperature in a flame-dried flask under argon was added potassium tert-butoxide (479 mg, 4.27 mmol; weighed under argon atmosphere) in three portions. The reaction mixture was stirred for 1.5 hours, poured on ice, the aqueous layer extracted twice with ethyl acetate and the combined organic layers discarded. The aqueous alkaline phase was acidified with cooling to pH 2-3 by addition of a 1N HCl solution and the product thoroughly extracted with ethyl acetate. The combined organic layers were dried over sodium sulfate and concentrated in vacuo. Yield: 500 mg of 3-methoxy-8-(2,4,6-trimethyl-phenyl)-tetrahydro-pyrazolo[1,2-a][1,2,5]triazepine-7,9-dione (compound P2.1) as a solid with a purity of 91% by LC-MS. This material (120 mg) was triturated in diethyl ether, filtered and dried to afford 110 mg of clean product, mp 229-230° C.

Workup

  1. additionpoured on ice
  2. extractionthe aqueous layer extracted twice with ethyl acetate
  3. temperaturewith cooling to pH 2-3 by addition of a 1N HCl solution
  4. extractionthe product thoroughly extracted with ethyl acetate
  5. dry with materialThe combined organic layers were dried over sodium sulfate
  6. concentrationconcentrated in vacuo
  7. customThis material (120 mg) was triturated in diethyl ether
  8. filtrationfiltered
  9. customdried

Sources & evidence

ORD record
ord-025aa97972ba40a3865471cb95c78989
Source dataset
uspto-grants-2016_03
Patent number
US09282743B2

Reaction notes

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