Acetyl chloride → Acetic acid 5-(4-methoxy-benzyl)-4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazin-2-ylmethyl ester

HRID 2046213Notes

Reaction equation

HRID 2046213 reaction equation
C(Cl)(=[O:3])C.[CH2:5]([O:7][C:8]([C:10]1[CH:28]=[C:13]2[C:14](=[O:27])[N:15]([CH2:18][C:19]3[CH:24]=[CH:23][C:22]([O:25][CH3:26])=[CH:21][CH:20]=3)[CH2:16][CH2:17][N:12]2[N:11]=1)=O)[CH3:6].C([O-])([O-])=O.[Na+].[Na+]>CN(C1C=CN=CC=1)C.C(Cl)Cl.C(Cl)(=O)C>[CH3:26][O:25][C:22]1[CH:23]=[CH:24][C:19]([CH2:18][N:15]2[CH2:16][CH2:17][N:12]3[N:11]=[C:10]([CH2:8][O:7][C:5](=[O:3])[CH3:6])[CH:28]=[C:13]3[C:14]2=[O:27])=[CH:20][CH:21]=1

Participants

7

Reactant 3

HCID 6367Acetyl chlorideHCID 10340Sodium CarbonateHCID 679762835-(4-Methoxy-benzyl)-4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester

Product 1

HCID 67975764Acetic acid 5-(4-methoxy-benzyl)-4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazin-2-ylmethyl esterYield 783.9%

Reagents, catalysts & solvents 3

HCID 6367Acetyl chlorideCatalystHCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

Acetyl chloride (0.043 mL, 0.055 mmol) was added to a stirred solution of 5-(4-methoxy-benzyl)-4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester (3.8 g, 11.5 mmol), TEA (0.1 mL, 0.75 mmol) and DMAP (6.1 mL, 0.05 mmol)) in DCM (2.5 mL) at 0° C. The mixture was stirred at room temperature for 2 hours. Then more acetyl chloride (0.01 mL, 0.01 mmol) was added and the mixture was stirred at room temperature for 2 hours more. The mixture was treated with a saturated solution of Na2CO3 and extracted with DCM. The organic layer was separated, dried (MgSO4), filtered and the solvents evaporated in vacuo to yield acetic acid 5-(4-methoxy-benzyl)-4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazin-2-ylmethyl ester (142 mg, 86% yield) as a colourless oil that was used in the next step without further purification.

Workup

  1. stirringthe mixture was stirred at room temperature for 2 hours more
  2. extractionextracted with DCM
  3. customThe organic layer was separated
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. customthe solvents evaporated in vacuo

Sources & evidence

ORD record
ord-6313ce2edc6349dfad75edb3abb0a73c
Source dataset
uspto-grants-2013_11
Patent number
US08592422B2

Reaction notes

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