ChemicalBook CAS DataBase List 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE

5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE synthesis

3synthesis methods

Product Name:5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE
CAS Number:57489-77-7
Molecular formula:C6H3Cl2N3
Molecular Weight:188.01

121-69-7 Synthesis

121-69-7
541 suppliers
$10.00/25mL

57489-70-0 Synthesis

Pyrazolo[1,5-a]pyrimidine-5,7(4H,6H)-dione

57489-70-0
58 suppliers
$21.00/100mg

57489-77-7
204 suppliers
$13.00/100mg

Yield:57489-77-7 80%

Reaction Conditions:

with trichlorophosphate

Steps:

5.A 5,7-Dichloropyrazolo[1,5-a]pyrimidine (J2)

5,7-Dichloropyrazolo[1,5-a]pyrimidine (J2)
POCl₃ (10 mL, 109 mmol) was added to a mixture of J1 (800 mg, 5.29 mmol) and dimethyl aniline (1.8 g, 14.82 mmol) in an ice-cooled round-bottom flask.
The reaction mixture was stirred at room temperature for 10 min and then heated to 60 °C for 3 h.
The excess POCl₃ was removed in vacuo, and the resulting residue was poured onto ice water.
The aqueous solution was basified to pH=9 with solid NaHCO₃.
The mixture was extracted with EtOAc (3x100 mL).
The combined organics were washed with brine, dried over MgSO₄, filtered, and concentrated in vacuo.
The resulting residue was purified by gradient elution on silica gel (20 to 80% EtOAc in heptane) to afford the title compound as a white solid (810 mg, 81%).
¹H NMR (300 MHz, CDCl₃): δ 8.22 (d, J = 3.0 Hz, 1H), 7.00 (s, 1H), 6.76 (d, J = 3.0 Hz, 1H) ppm; LRMS m/z (M+H) 188.1 found, 188.0 required.