2-Chloroquinazoline

To a mixture of 2, 4-dichloroquinazoline (5.0 g, 25 mmol), sodium chloride (0.7 g, 13 mmol) and ammonium hydroxide (27.3 g, 779 mmol) in dichloromethane (100 mL) and water (70 ml) was added zinc (4.93 g, 75.4 mmol). The mixture was stirred at 40 C for 4 hour under nitrogen, then poured into water and extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by silica gel chromatography [petroleum ether: ethyl acetate = 5:11 to give compound B-7 (2.0 g, 43% yield) as a white solid. 'HNMR (CD3OD, 400 MHz): 9.46 (s, 1H), 7.16 (d, J8.4 Hz, 1H), 8.07 (t, J8.4 Hz, 1H), 7.95 (d, J=8.4 Hz, 1H), 7.78 (t, J7.6 Hz, 1H).A mixture of 24 (900 mg, 0.502 mmol), Zn-powder (900 mg, 1.53 mmol), saturated NaCl with 9% NH3 (2 ml) and CH2Cl2 (2 ml) was heated 15 min at 100 C using microwave synthesizer. The resulting reaction mixture was dissolved in ethyl acetate (100 ml) and washed with HCl (1 M) (2× 100 ml) and H2O (2× 100 ml). The organic phase was dried (Na2SO4) and evaporated to dryness. The crude product was purified by flash chromatography (silica gel) eluting with EtOAc/PE 1:10 to give 15 (82 mg, 13%). 1H NMR (CDCl3): delta 9.31 (s, 1H); 8.02-7.95 (m, 3H); 7.70 (t, 1H, J = 7.4 Hz); 7.77 (d, 1H, J = 8.1 Hz); 7.59 (t, 1H, J = 7.6 Hz). 13C NMR (CDCl3): delta 163.0; 157.6; 151.9; 135.5; 128.3; 127.6; 127.3; 123.4.A two-phase mixture of a solution of 2, 4-dichloroquinazoline (5 g) in methylene chloride (100 mL) covered with 100 mL of saturated brine containing 9% NH4OH is treated with powdered zinc (5 g) and the resultant mixture is then refluxed for 4 h, cooled and filtered through celite. The organic layer is removed, diluted with ethyl acetate (100 ml), washed with 1 N HCl solution, dried and concentrated.To a mixture of General procedure: Hydrazine hydrate (5 mL) and 19, 20, 22, 23a-c, 24a, 24b (10 mmol) was added to EtOH, and the mixture was heated to 60C overnight. After cooling, the solvent was evaporated, and the residue was diluted with 50mL water, and extracted with DCM (50 mL×3). The combined organic extract was washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuoto get the target products 25a-h.To a mixture of

Molecular Weight:164.59
XLogP3:2.6
Hydrogen Bond Acceptor Count:2
Exact Mass:164.0141259
Monoisotopic Mass:164.0141259
Topological Polar Surface Area:25.8
Heavy Atom Count:11
Complexity:140
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes