Hydrochloric Acid → (rac)-7-hydroxy-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one

HRID 2046185Notes

Reaction equation

Cl.C[O:3][CH:4](OC)[CH2:5][NH:6][C:7]([C:9]1[NH:10][N:11]=[C:12]([CH2:14][O:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)[CH:13]=1)=[O:8]>O.CC(C)=O>[OH:3][CH:4]1[N:10]2[N:11]=[C:12]([CH2:14][O:15][C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)[CH:13]=[C:9]2[C:7](=[O:8])[NH:6][CH2:5]1

Participants

Conditions

Temperature: 100 °C

Procedure

A 2M solution of HCl in H2O was added to a solution of 5-phenoxymethyl-2H-pyrazole-3-carboxylic acid (2,2-dimethoxy-ethyl)-amide (1.25 g, 4.09 mmol) in acetone (7 mL). The mixture was stirred at 100° C. for 5 minutes under microwave irradiation. The solvent was evaporated in vacuo and the residue was supported on silica gel and purified by flash column chromatography (silica; AcOEt in DCM 0/100 to 100/0, then MeOH in AcOEt 0/100 to 10/90). Desired fractions were collected and the solvents evaporated in vacuo. The residue was triturated with diethyl ether to yield (rac)-7-hydroxy-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one (286 mg, 30% yield) as an off-white solid.

Workup

customThe solvent was evaporated in vacuo
custompurified by flash column chromatography (silica
customDesired fractions were collected
customthe solvents evaporated in vacuo
customThe residue was triturated with diethyl ether

Sources & evidence

ORD record: ord-c9a1496c8aa643eaa9727f93f02bdc0b
Source dataset: uspto-grants-2013_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08592422B2

Reaction notes

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