5-AMINO-3-ETHYL-1H-PYRAZOLE

To a stirred solution of 3-oxopentanenitrile (XXXV; 2g; 21 mmol) in ethanol (60 mL) was added hydrazine hydrate (1.3 mL; 41 mmol). The reaction mixture was heated to a reflux for12 hours. The reaction mixture was cooled and concentrated under reduced pressure. The crude mixture was purified by column chromatography using 8percent MeOH-DCM to obtain 5-ethyl-1H- pyrazol-3-amine as a brown sticky solid (XXXVI; 1.8 g; 78percent yield). ‘H NMR (400 MHz, DMSO-d6): ö 11.0 (bs, 1H), 5.17 (s, 1H), 4.5 (bs, 2H), 2.4 (m, 2H), 1.1 (m, 3H). MS (M+1):111.93.A mixture of a portion (0.6 g) of the material so obtained, hydrazine hydrate (0.28 ml) and ethanol (45 ml) was heated at 70°C for 12 hours. The solvent was evaporated and the residue was purified by column chromatography on silica using a 19:1 mixture of methylene chloride and methanol as eluent. There was thus obtained the required starting material in 51percent yield; To a solution of (A) In the same manner as described in the step (A) of Reference Example 19, 9.97 g of N-(5-ethyl-1H-pyrazol-3-yl)acetamidine hydrochloride was obtained from 12.9 g of 30 mg of 4-amino-1-cyclopentyl-1H-pyrazolo[3, 4-d]pyrimidine-3-carboxylic acid obtained in step 2 of Reference Example 1, 16 mg of 2, 4-Dichloro-5-methoxypyrimidine (2.79 mmol, 0.50 g) and the compound prepared in Step 1 (3.07 mmol) were stirred at room temperature DIPEA (N, N-diisopropylethylamine) was added to isopropanol (30 ml), and the mixture was stirred and heated to 60 C for 5 hours. After the reaction was terminated, the reaction mixture was cooled to room temperature, and the solvent was removed under reduced pressure. Methanol/dichloromethane To give the desired compound in 68% yield.

Molecular Weight:111.15
XLogP3:0.7
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:111.079647300
Monoisotopic Mass:111.079647300
Topological Polar Surface Area:54.7
Heavy Atom Count:8
Complexity:74.1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes