Nitrogen → Isopropyl 4-(3-bromopyrazolo[1,5-a]pyrimidin-5-yl)piperazine-1-carboxylate

HRID 1844346Notes

Reaction equation

HRID 1844346 reaction equation
N#N.[Br:3][C:4]1[CH:5]=[N:6][N:7]2[CH:12]=[CH:11][C:10]([N:13]3[CH2:18][CH2:17][NH:16][CH2:15][CH2:14]3)=[N:9][C:8]=12.CCN(C(C)C)C(C)C.Cl[C:29]([O:31][CH:32]([CH3:34])[CH3:33])=[O:30]>C(OCC)(=O)C.C1(C)C=CC=CC=1>[CH:32]([O:31][C:29]([N:16]1[CH2:17][CH2:18][N:13]([C:10]2[CH:11]=[CH:12][N:7]3[N:6]=[CH:5][C:4]([Br:3])=[C:8]3[N:9]=2)[CH2:14][CH2:15]1)=[O:30])([CH3:34])[CH3:33]

Participants

7

Reactant 4

HCID 947NitrogenHCID 7917Isopropyl chloroformateHCID 81531DiisopropylethylamineHCID 866974343-Bromo-5-(piperazin-1-yl)pyrazolo[1,5-a]pyrimidine

Product 1

HCID 86697433Isopropyl 4-(3-bromopyrazolo[1,5-a]pyrimidin-5-yl)piperazine-1-carboxylate

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a rapidly stirred, 0° C., N2 blanketed, solution of 3-bromo-5-piperazin-1-yl-pyrazolo[1,5-a]pyrimidine (15.8 g, 56.0 mmol) and Hunig's base [7087-68-5] (20.0 mL, 114.8 mmol) in ethyl acetate (280 mL) was steadily added a 1.0M solution of isopropyl chloroformate in toluene (67.0 mL) over the course of 10 minutes. The reaction was allowed to stir and warm to ambient temperature over night at which time it was washed with brine, dried (MgSO4), preloaded onto silica gel, chromatographed (Silica gel, eluted with 100% ethyl acetate) and crystallized from ethyl acetate/heptane to afford 13.2 g of white powder, mp. 78-79° C. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.22 (d, J=6.32 Hz, 6 H) 3.44-3.54 (m, 4 H) 3.67-3.79 (m, 4 H) 4.82 (spt, J=6.23 Hz, 1 H) 6.77 (d, J=7.83 Hz, 1 H) 7.97 (s, 1 H) 8.69 (d, J=7.83 Hz, 1 H). 13C NMR (100 MHz, DMSO-d6) δ ppm 21.94, 42.80, 43.87, 68.17, 77.32, 97.66, 136.47, 143.87, 144.40, 154.29, 155.64. LRMS (ESI) m/z 368.0/370.0 [(M+H)]+, calc'd for C14H18BrN5O2: 368.24.

Workup

  1. stirringto stir
  2. temperaturewarm to ambient temperature over night at which time it
  3. washwas washed with brine
  4. dry with materialdried (MgSO4)
  5. customchromatographed
  6. wash(Silica gel, eluted with 100% ethyl acetate)
  7. customcrystallized from ethyl acetate/heptane

Sources & evidence

ORD record
ord-1b4f23e9ab074a85b75900db96768cff
Source dataset
uspto-grants-2015_02
Patent number
US08946415B2

Reaction notes

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