2,4-DICHLORO-5-NITROPYRIDINE

Light yellow needles

Step 3.2, 4-Dichloro-5-nitropyridine The product from Step 2 (40.0 g, 229 mmol) was suspended in toluene (300 mL) and POC13 (65 mL, 697 mmol) was added over 10 min, then the mixture was heated to relux for 6 h then cooled to 60 °C and allowed to stir overnight at that temperature. The heterogeneous mixture was cooled and concentrated, the residue was carefully made basic with aq. K2CO3 solution and extracted with EtOAc. The organic layers were combined, washed with H20 and brine, dried (Na2S04), filtered and the filtrate was concentrated to give an oil. The crude oil was passed through a plug of silica gel (50percent EtOAc in hexanes) to give the title compound (32.5 g, 74 percent) as an orange oil which solidified on standing. MS (ES+) m/e 194 [M+H] +.Step 3.2, 4-Dichloro-5-nitropyridine The product from Step 2 (40.0 g, 229 mmol) was suspended in toluene (300 mL) and POC13 (65 mL, 697 mmol) was added over 10 min, then the mixture was heated to relux for 6 h then cooled to 60 °C and allowed to stir overnight at that temperature. The heterogeneous mixture was cooled and concentrated, the residue was carefully made basic with aq. K2CO3 solution and extracted with EtOAc. The organic layers were combined, washed with H20 and brine, dried (Na2S04), filtered and the filtrate was concentrated to give an oil. The crude oil was passed through a plug of silica gel (50percent EtOAc in hexanes) to give the title compound (32.5 g, 74 percent) as an orange oil which solidified on standing. MS (ES+) m/e 194 [M+H] +.4-Chloro-2-hydroxy-5-nitropyridine (17.2 g, 98.6 mmol) was suspended in toluene (150 mL) before careful addition of phosphorus oxychloride (28 mL, 300 mmol) over 20 minutes. A suspension of 2-hydroxy-4-chloro-5-nitropyridine (86.2 mmol, 15 g) in phosphorus oxychloride (50 mL) was heated at 80°C for 3.5 hours. The excess phosphorus oxychloride was removed under reduced pressure and the residue partitioned between dichloromethane and 10percent aqueous sodium carbonate solution. The aqueous phase was further extracted with dichloromethane (3 x 100 mL) . The combined organic extracts were dried (MgS0Fuming HTo 4-chloro-5-nitropyridine-2-amine (Method 92, 4.40 g, 21.0 mmol) in concentrated HCl (70 ml) was added sodium nitrite (4.36 g, 63.1 mmol) potion wise at 0-5

2,4-Dichloro-5-nitropyridine is used in the synthesis of potent and selective stearoyl-CoA desaturase (SCD) inhibitors. Also used in preparation of Rho-Kinase inhibitors displaying antihypertensive ac tivity.

Molecular Weight:192.98
XLogP3:2.3
Hydrogen Bond Acceptor Count:3
Exact Mass:191.9493327
Monoisotopic Mass:191.9493327
Topological Polar Surface Area:58.7
Heavy Atom Count:11
Complexity:161
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes