4,6-DICHLORO-1H-PYRAZOLO[3,4-D]PYRIMIDINE

Yellow solid

(2) Step 2: To a solution of 1f (38.0g, 0.18mol, 1eq) in methanol (700mL) was added drop-wise a solution of hydrazine monohydrate (9.2mL) in methanol (180mL) at -10To 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 the title compound (10.3 g, 62percent yield) as a yellow solid. ‘H NMR (CDC13, 400IVIHz): 11.56 (br, 1H), 8.43 (s, 1H). MS m/z 190.68 [M+1].At -10 willCompound 3 (100 mg, 0.47 mmol)In methanol was slowly added dropwise to a methanolic solution of hydrazine hydrate (0.024 ml)A solution of triethylamine (0.067 ml) in methanol was then added dropwiseTo the above mixture, Continue at -10 Reaction time 30 min.TLC detection (PE: EA = 2: 1), Raw material reaction is complete, Spin drying solvent, Column chromatography (PE: EA = 10: 1) gaveWhite solid 4 (50 mg), yield 56.3percentTo a solution of 2, 4, 6-trichloropyrimidine-5-carbaldehyde (3.50 g, 16.6 mmol) in THF (50 mL)was added N2H4.H20 (830 mg, 16.6 mmol) slowly at-lO °C. Then, Et3N (2.51 g, 24.9 mmol)was added to the mixture at -10 00. The mixture was stirred at -10 °C for 30 mm. The mixture was concentrated. The residue was purified by column chromatography (petroleum ether: ethyl acetate = 10: 1) to give the title compound (1.25 g, yield 40percent) as a yellow solid. 1H NMR (300 MHz, CDCI3): 611.61 (brs, 1H), 8.25 (s, IH).LCMS [mobile phase: 5-95percent CH3CNJ: Rt = 2.005 mm;MS Calcd: 188; MS Found: 189 [M+H].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, 87percent); mp: 173-175 °C.

Molecular Weight:189.00
XLogP3:2.1
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Exact Mass:187.9656515
Monoisotopic Mass:187.9656515
Topological Polar Surface Area:54.5
Heavy Atom Count:11
Complexity:155
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes