Pyridine → 2-(3-Bromo-1-(3-chloropyridin-2-yl)-1H-pyrazol-5-yl)-6-chloro-8-methyl-4H-benzo[d][1,3]oxazin-4-one

Temperature

-5 °C

Methanesulfonyl chloride (1.0 mL, 1.5 g, 13 mmol) was dissolved in acetonitrile (10 mL), and the mixture was cooled to −5° C. A solution of 3-bromo-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxylic acid (i.e. the pyrazolecarboxylic acid product of Example 5, Step D) (3.02 g, 10 mmol) and pyridine (1.4 mL, 1.4 g, 17 mmol) in acetonitrile (10 mL) was added dropwise over 5 minutes at −5 to 0° C. A slurry formed during the addition. The mixture was stirred 5 minutes at this temperature, and then a mixture of 2-amino-3-methyl-5-chlorobenzoic acid (i.e. the product of Example 1 Step A) (1.86 g, mmol) and pyridine (2.8 mL, 2.7 g, 35 mmol) in acetonitrile (10 mL) was added, rinsing with more acetonitrile (5 mL). The mixture was stirred 15 minutes at −5 to 0° C., and then methanesulfonyl chloride (1.0 mL, 1.5 mL, 13 mmol) in acetonitrile (5 mL) was added dropwise over. 5 minutes at a temperature of −5 to 0° C. The reaction mixture was stirred minutes more at this temperature, then allowed to warm slowly to room temperature, and stirred 4 h. Water (20 mL) was added dropwise, and the mixture was stirred 15 minutes. Then the mixture was filtered, and the solids were washed with 2:1 acetonitrile-water (3×3 mL), then with acetonitrile (2×3 mL), and dried under nitrogen to afford the title product as a light yellow powder, 4.07 g (90.2% crude yield), melting at 203-205° C. HPLC of the product using a Zorbax® RX-C8 chromatography column (4.6 mm×25 cm, eluent 25-95% acetonitrile/pH 3 water) showed a major peak corresponding to the title compound and having 95.7% of total chromatogram peak area.

1. customA slurry formed during the addition
2. additionwas added
3. washrinsing with more acetonitrile (5 mL)
4. stirringThe mixture was stirred 15 minutes at −5 to 0° C.
5. custom5 minutes
6. customat a temperature of −5 to 0° C
7. stirringThe reaction mixture was stirred minutes more at this temperature
8. temperatureto warm slowly to room temperature
9. stirringstirred 4 h
10. stirringthe mixture was stirred 15 minutes
11. filtrationThen the mixture was filtered
12. washthe solids were washed with 2:1 acetonitrile-water (3×3 mL)
13. dry with materialwith acetonitrile (2×3 mL), and dried under nitrogen

ORD record

ord-4db306cd6ec14fffbd9262da9c3efa0e

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08158802B2