5-Methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine-2-carboxylic acid hydrochloride

5-Methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine-2-carboxylic Acid Hydrochloride is used as a reagent in the synthesis of N-(2-acylaminobenzyl or 2-acylaminoheterocyclylmethyl)thiophene-2-carboxamide derivatives as antithrombotics. It is also used as a reagent in the synthesis of diamide derivatives as FXa inhibitors. 5-Methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine-2-carboxylic Acid Hydrochloride is an intermediate for Edoxaban (E555520).

2-cyano-5-methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine hydrochloride monohydrate (500.61 mg), ethanol (5 mL), and 4N aqueous lithium hydroxide (1.34 mL) were mixed at room temperature, and the resultant mixture was stirred at 50 °C for 7 hours. Until the reaction mixture was cooled with ice-water, 1N HCl in ethanol (7.5 mL) was added to the mixture. It was stirred for 1.5 hours. The precipitated crystals were collected by filtration, and were washed with ethanol (2 mL). The wet crystal was dried at room temperature under reduced pressure to obtain 5-Methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine-2-carboxylic acid hydrochloride.