Yield:50878-90-5 80%

Reaction Conditions:

with hydrogenchloride;tin(II) chloride dihdyrate in water at 50;

Steps:

Intermediate 20: 3-amino-4-methylquinoline

A solution of 4-methyl-3-nitroquinoline (500 mg, 2.66 mmol) in cone. HCI (10 mL) was heated to 50 °C. Tin (II) chloride dihydrate (1.5 g, 6.6 mmol) was added. The mixture was stirred at 50 °C overnight. The mixture was diluted with water (20 mL). The mixture was adjusted to pH 9 by addition of 5N aqueous sodium hydroxide. The mixture was cooled to 4 °C and extracted twice with ethyl acetate (30 mL). The combined extracts were washed with ice-cold water (40 mL) and dried over anhydrous Na2S0₄, filtered, and concentrated to give 3-amino-4-methylquinoline (340 mg, 80%) as a yellow solid. ¹ H NMR (400 MHz, CDCI₃) δ 8.42 (s, 1 H), 7.89-7.91 (m, 1 H), 7.79-7.82 (m, 1 H), 7.44-7.38 (m, 2H), 3.77 ( br s, 2H), 2.37 (s, 3H).

References:

WO2013/14569,2013,A1 Location in patent:Page/Page column 35