Hydrochloric Acid → 6-(4-tert-butyl-phenyl)-2-hydroxymethyl-5H-pyrazolo[1,5-a]pyrazin-4-one

HRID 2272956Notes

Reaction equation

HRID 2272956 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].C([O:9][C:10]([C:12]1[CH:31]=[C:15]2[C:16](=[O:30])[NH:17][C:18]([C:20]3[CH:25]=[CH:24][C:23]([C:26]([CH3:29])([CH3:28])[CH3:27])=[CH:22][CH:21]=3)=[CH:19][N:14]2[N:13]=1)=O)C.Cl>C1COCC1.CO>[C:26]([C:23]1[CH:22]=[CH:21][C:20]([C:18]2[NH:17][C:16](=[O:30])[C:15]3[N:14]([N:13]=[C:12]([CH2:10][OH:9])[CH:31]=3)[CH:19]=2)=[CH:25][CH:24]=1)([CH3:29])([CH3:27])[CH3:28]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 21226445Aluminium lithium hydrideHCID 898263626-(4-Tert-butyl-phenyl)-4-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester

Product 1

HCID 717654606-(4-tert-butyl-phenyl)-2-hydroxymethyl-5H-pyrazolo[1,5-a]pyrazin-4-one

Reagents, catalysts & solvents 2

HCID 887MethanolCatalystHCID 8028TetrahydrofuranSolvent

Procedure

Under nitrogen, 43.4 mg (1.14 mmol) lithiumaluminiumhydride is added to a solution of 194 mg (0.571 mmol) 6-(4-tert-butyl-phenyl)-4-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrazine-2-carboxylic acid ethyl ester (for preparation see previous example) in 20 ml THF. The reaction mixture is stirred at ambient temperature for two hours. A few drops of methanol and then 2 ml 2 N aqueous HCl solution are added slowly to the reaction mixture. It is then filtered over a pad of celite. The filtrate is evaporated and the residue is chromatographed on a silica gel column with cyclohexane/ethyl acetate as eluent to give 6-(4-tert-butyl-phenyl)-2-hydroxymethyl-5H-pyrazolo[1,5-a]pyrazin-4-one (“A18”) as white powder; HPLC/MS: 1.72 (C), [M+H] 298; 1H NMR (400 MHz, DMSO-d6) δ [ppm] 11.46 (s, 1H), 7.94 (s, 1H), 7.67 (d, J=8.5, 2H), 7.49 (d, J=8.5, 2H), 6.91 (s, 1H), 5.28 (bs, 1H), 4.59 (s, 2H), 1.31 (s, 9H).

Workup

  1. filtrationIt is then filtered over a pad of celite
  2. customThe filtrate is evaporated
  3. customthe residue is chromatographed on a silica gel column with cyclohexane/ethyl acetate as eluent

Sources & evidence

ORD record
ord-6f523dba428d4807b19d0d3db3b9150f
Source dataset
uspto-grants-2015_09
Patent number
US09120805B2

Reaction notes

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