ChemicalBook CAS DataBase List 4,6-Dichloro-1H-pyrazolo[3,4-d]pyrimidine

4,6-Dichloro-1H-pyrazolo[3,4-d]pyrimidine synthesis

3synthesis methods

Product Name:4,6-Dichloro-1H-pyrazolo[3,4-d]pyrimidine
CAS Number:42754-96-1
Molecular formula:C5H2Cl2N4
Molecular Weight:189

To a solution of 2,4,6-trichloropyrimidine-5-carbaldehyde (19.0 g, 990 mmol) in methanol (300 mL) was added drop-wise a solution of hydrazine monohydrate (4.8 mL) in methanol (80 mL) at 0 °C followed by drop-wise addition of triethylamine (13 mL) in methanol (80 mL) at 0 °C. The mixture was stirred at the same temperature for 30 mm. The solvent was removed, and the residue was purified by flash chromatography to afford 4,6-Dichloro-1H-pyrazolo[3,4-d]pyrimidine (10.3 g, 62 % yield) as a yellow solid. ‘H NMR (CDC13, 400IVIHz): 11.56 (br, 1H), 8.43 (s, 1H). MS m/z 190.68 [M+1].

2465-59-0 Synthesis

2465-59-0
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$29.00/250mg

4,6-Dichloro-1H-pyrazolo[3,4-d]pyrimidine

42754-96-1
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$7.00/100mg

Yield:42754-96-1 87%

Reaction Conditions:

Stage #1:oxypurinol with trichlorophosphate at 20; for 0.25 h;
Stage #2: with triethylamine at 55 - 110; for 5.16667 h;

Steps:

4 4.5. 4,6-Dichloro-1H-pyrazolo[3,4-d]pyrimidine (4)
To 1,7-dihydro-pyrazolo[3,4-d]pyrimidine-4,6-dione (3) (1.233 mol), phosphorous oxychloride (2.84 mol) was added withstirring at 20 °C. After stirring for 15 min, the mixturewas heated at 55 °C, and triethylamine (2.53 mol) was added over a period of 1 h at a rate that maintains the internal temperature below 65 °C, then mixturewas slowly heated to an internal temperature of 85 °C for 10 min and then heated at 108-110 °C for 4 h to obtain a clear brown-yellow solution. The reaction mixture was cooled to an internal temperature of 40 °C and warm water was added over aperiod of 30-40 min. The solid was collected by filtration to afford pure 4,6-dichloro-1H-pyrazolo[3,4-d]pyrimidine (4) as light yellow solid; (5.35 g, 87%); mp: 173-175 °C.

References:

Singla, Prinka;Luxami, Vijay;Singh, Raja;Tandon, Vibha;Paul, Kamaldeep [European Journal of Medicinal Chemistry,2017,vol. 126,p. 24 - 35]

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50270-27-4 Synthesis