6-Nitro-4H-benzo[1,4]oxazin-3-one

Preparation 8; 6-Amino-7-ethyl-4-methyl-4H-benzo[1, 4]oxazin-3-oneThe synthetic procedure used in this preparation is outlined in Scheme H. Step 1 6-Nitro-4H-benzo[1, 4]oxazin-3-oneA solution of 2-Amino-4-nitro phenol (6.0 g, 38.93 mmol) in methylene chloride (200 ml) was cooled to 0° C. Triethyl amine (16.3 ml, 116.9 mmol) was added followed by chloroacetyl chloride (3.42 ml, 42.8 mmol) portionwise. The mixture was stirred at room temperature for 18 hours, then diluted with methylene chloride. The organic phase was washed with water, dried over MgSOA mixture of 2-amino-4-nitrophenol (3A, 25.03 g, 0.16 mol) in 4-methyl-2-pentanone and water (420 mL, 1:1) was treated with sodium bicarbonate (32.74 g, 0.39 mol), cooled to 0° C., and treated then with chloroacetyl chloride (15.52 mL, 0.19 mol). The reaction mixture was heated to reflux overnight. After cooling to RT, the mixture was concentrated under vacuum. The residue was diluted with water (200 mL) and EtOAc (100 mL), and filtered to give the pale gray solid 3B (26.05 g). The filtrate was separated and the aqueous was extracted with EtOAc (3.x.100 mL). The combined organic layers were washed with water, and dried (MgSOTo a solution of the 4- or 5-nitro-2-aminophenol (400 mg, 1 equiv) in isobutylmethylketone (4 mL) was added NaHCOA mixture of 2-amino-4-nitrophenol (5.OOg, 32.44mmol), 2-chloroacetyl chloride (4.03g, 35.69mmol) and DCM (5OmL) was cooled to 0°C. TEA (9.85g, 97.33mmol) was added dropwise, the resulting mixture was stirred at 20°C for 20 hours. The reaction mixture was concentrated under reduced pressure and water (100 mL) was added, the precipitate was filtered to afford the compound 7a as a brown solid (5.71g, 90percent). MS: 195(M+H).To a cooled to 0° C. solution of 2-amino-4-nitrophenol (4 g, 26 mmol) in acetone (50 mL) chloroacetyl chloride (3.3 g, 29 mmol) was added dropwise. A slight warming-up and precipitation were observed. Then EtEXAMPLE E-1 EXAMPLE E-1 [Example 1-1]; Reaction 1; To a solution of 2-amino-4-nitrophenol (3.08g, 20.0mmol) and pyridine (1.58g, 20.0mmol) in DMF was added chloroacetyl chloride (2.26g, 20.0mmol) at 0°C and the mixture was stirred for Ih. NaH (60percent in oil, 0.80g, 20.0mmol) was added to the reaction mixture at 0°C and the mixture was stirred for 2h. The reaction was quenched by addition of water and extracted with ethyl acetate (EtOAc). The combined extracts were washed with water, brine, dried, and evaporated. The residue was purified by recrystallization from EtzO. 1: 3.19g, (82.0percent), brown solid.A suspension of 2-amino-4-nitrophenol (7.7 g, 50 mmol) was prepared in 125 mL chloroform. Step 15a: 6-nitro-2H-benzo[b][1, 4]oxazin-3(4H)-one (Intermediate 15a)To a stirred solution of 2-amino-4-nitrophenol (3 g, 19.4 mmol) in DMF (25 mL) was added pyridine (1.6 mL, 19.4 mmol) and chloroacetyl chloride (1.53 mL, 19.4 mmol) at 0° C. The reaction mixture was stirred for 1 h at RT followed by addition of 60percent NaH (780 mg, 19.4 mmol) and continued stirring for another 2 h at RT. After the completion of reaction (monitored by TLC), the reaction was quenched with ice cold water (150 mL), precipitated solid was filtered and dried to afford 15a (2 g, 54percent) as off white solid. TLC: 60percent Ethyl acetate/hexane (RStep 7a: At 0° C., chloroacetyl chloride (8.75 mL, 0.11 mol) was added dropwise to a mixture of 4-nitro-2-aminophenol (15.4 g, 0.1 mol), benzyltrimethylammonium chloride (18.6 g, 0.1 mol) and NaHCOIntermediate 43; Preparation of 3, 4-dihydro-2H-benzo[b][1, 4]oxazin-6-amine; 6-Nitro-2H-benzo[b][1, 4]oxazin-3(4H)-one Bromoacetyl bromide (4.84 g, 24 mmol, in 10 mL CHClIntermediate 6 Preparation of 3, 4-dihydro-2H-benzo[b][1, 4]oxazin-6-amine; 6-Nitro-2H-benzo[b][1, 4]oxazin-3(4H)-one Bromoacetyl bromide (4.84 g, 24 mmol, in 10 mL CHCla. a. Intermediate 7b

Molecular Weight:194.14
XLogP3:0.7
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Exact Mass:194.03275668
Monoisotopic Mass:194.03275668
Topological Polar Surface Area:84.2
Heavy Atom Count:14
Complexity:263
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes