1,1-Dimethylethyl N-(4-formyl-3-pyridinyl)carbamate

A solution of tert-butyl pyridin-3-ylcarbamate (17.7 g, 91.1 mmol) in THF (300 mL) was cooled to -78 (100 mg) was dissolved in a hydrochloric acid-methanol solution (2.0 ml), and the solution was stirred under reflux for 30 min. The solvent was removed by distillation under the reduced pressure. 1-Chloro-propan-2-one (42 mg) dissolved in a 5 N aqueous sodium hydroxide solution (0.5 ml) was added to the residue, and the mixture was allowed to stand in an airtightly stoppered state for two days. The reaction mixture was neutralized with 10% hydrochloric acid, and dichloromethane was then added thereto for extraction. The dichloromethane layer was washed with water and saturated brine and was dried over magnesium sulfate. The solvent was removed by distillation under the reduced pressure, and the residue was purified by column chromatography with a chloroform-acetone system to give 2-methyl-[1, 7]naphthyridin-3-ol (22 mg, yield 31%). 2-Methyl-[1, 7]naphthyridin-3-ol (22 mg), 4-chloro-6, 7-dimethoxyquinoline (92 mg), and 4-dimethylaminopyridine (50 mg) were suspended in 1, 2-dichlorobenzene (1.5 ml), and the suspension was stirred at 140C for 8.5 hr. The reaction mixture was cooled to room temperature, and water was added thereto. The mixture was extracted with chloroform, and the chloroform layer was washed with water and saturated brine and was dried over anhydrous magnesium sulfate. The solvent was removed by distillation under the reduced pressure, and the residue was purified by column chromatography with a chloroform-methanol system to give the title compound (25 mg, yield 53%). 1H-NMR (CDCl3, 400 MHz): delta 2.76 (s, 3H), 4.01 (s, 3H), 4.06 (s, 3H), 6.54 (d, J = 5.6 Hz, 1H), 7.44 (s, 1H), 7.49 (s, 1H), 7.52 (d, J = 6.0 Hz, 1H), 7.61 (s, 1H), 8.57 (m, 2H), 9.45 (s, 1H) Mass spectrometric value (ESI-MS, m/z): 348 (M+1)+ Step 2, Method 8: tert-But l iV-[4-(6-Methoxy-l, 3-benzothiazol-2-yl)pyridin-3- yl] carbamate[0172] To a stirred solution of 2-[(2-amino-5-methoxyphenyl)disulfonyl]-4- methoxyaniline (100 mg, 0.324 mmol) and te^butyl(4-formylpyridin-3-yl)carbamate (144 mg, 0.648 mmol) in N, N-dimethylformamide (3 mL) under nitrogen was added sodium metabisulfite (123 mg, 0.648 mmol). The reaction mixture was heated to 130 C and stirred for 1.5 hours. The mixture was allowed to cool to room temperature then ethyl acetate (10 mL) and water (10 mL) added and thelayers separated. The organic layer was washed with water (2 x 10 mL) and brine (2 x 10 mL). The combined organic layers were dried over magnesium sulphate, concentrated, recrystallised twice from methanol (8 mL) and the resulting solid dried under suction to give the title compound 50 mg (21% yield) as an off-white powder. 5H NMR (500 MHz, DMSO) 10.76 (s, 1H), 9.32 (s, 1H), 8.43 (d, J = 5.1 Hz, 1H), 7.98 (d, J = 9.0 Hz, 1H), 7.89 (d, J = 5.1 Hz, 1H), 7.82 (d, J = 2.5 Hz, 1H), 7.22 (dd, J = 9.0, 2.5 Hz, 1H), 3.88 (s, 3H), 1.49 (s, 9H). Tr(MET-uHPLC-AB-lOl) = 4.1 min, (ES+) (M+H)+358.

Molecular Weight:222.24
XLogP3:1.4
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:4
Exact Mass:222.10044231
Monoisotopic Mass:222.10044231
Topological Polar Surface Area:68.3
Heavy Atom Count:16
Complexity:260
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes