tert-Butyl piperazine-1-carboxylate → tert-Butyl 4-(5-chloro-pyrazolo[1,5-a]pyrimidin-7-yl)piperazine-1-carboxylate

HRID 333968Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[C:6](Cl)[N:5]2[N:9]=[CH:10][CH:11]=[C:4]2[N:3]=1.[N:12]1([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1>COCC(O)C>[Cl:1][C:2]1[CH:7]=[C:6]([N:15]2[CH2:14][CH2:13][N:12]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:17][CH2:16]2)[N:5]2[N:9]=[CH:10][CH:11]=[C:4]2[N:3]=1

Participants

Conditions

Temperature: 110 °C

Procedure

5,7-Dichloro-pyrazolo[1,5-a]pyrimidine (980 mg, 5.2 mmol) and tert-butyl piperazine-1-carboxylate (2.3 g, 12.6 mmol) were dissolved in 1-methoxy-2-propanol (40 ml) and heated under microwave irridation at 110° C. for one hour. The solvent was removed under reduced pressure and the residue purified by column chromatography (silica, pentane/ethylacetate). The raw product was crystallized from ethanol to yield 1.23 g of a crystalline solid (3.65 mmol, 70%). MS (APCI): m/z=338.2 [M+1]+.

Workup

customThe solvent was removed under reduced pressure
customthe residue purified by column chromatography (silica, pentane/ethylacetate)
customThe raw product was crystallized from ethanol

Sources & evidence

ORD record: ord-f3a9ade4a0c8497993728af6f8daaba8
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08883791B2

Reaction notes

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