Thiazolo[5,4-c]pyridine, 4,5,6,7-tetrahydro-5-methyl-

17899-48-8

259809-24-0

General procedure for the synthesis of 4,5,6,7-tetrahydro-5-methyl-thiazolo[5,4-c]pyridin-2-amine from 5-methyl-4,5,6,7-tetrahydro-4,5,6,7-tetrahydro-5-methyl-thiazolo[5,4-c]pyridin-2-amine: in the microchannel reaction device, a connecting tube with a diameter of 2.1 mm was configured with the length of the inlet tube of 15 cm, and the length of the connecting tube between the T-valve and microchannel reactor was 25 cm , and the length of the connecting tube between the microreactor and the outlet was 20 cm. 3.84 mL of concentrated sulfuric acid and 5.6 mL of hypophosphorous acid were dissolved in 30 mL of distilled water, and the temperature was controlled to be at 5 °C. 4.7 g of 5-methyl-4,5,6,7-tetrahydro[1,3]thiazolo[5,4-c]pyridin-2-amine was dissolved in the above solution in a total volume of 50 mL, and the temperature was controlled at 0 °C. Another 0.2484 g of sodium nitrite was dissolved in 20 mL of water to a volume of 25 mL and the temperature was controlled at 0°C. After both solutions were cooled to 0°C, they were simultaneously pumped at a flow rate of 0.15 mL/min and 0.075 mL/min into a microchannel reactor (reactor volume of 10 mL, inner diameter of 1 mm) through a T-shaped mixing valve at a reaction temperature of 0°C. After 22 min of reaction, the reaction solution was transferred to a flask, and the pH was adjusted to 13 by adding 12 mol/L sodium hydroxide solution, and the temperature was controlled not to exceed 25 °C. Extraction was carried out with toluene, and the supernatant was collected and the target product was obtained by liquid phase separation in 75% yield.