Methane → 1h,3h-Pyrrolo[1,2-c]thiazole-7-carboxamide

Participants

Reaction Conditions

Reaction Steps

Hydrochloride of the acid chloride derived from (+)-3-(3-pyridyl)-1H,3H-pyrrolo[1,2-c]thiazole-7-carboxylic acid (5.4 g) is added, at a temperature between 60° and 62° C., to a solution of 3-amino-4-chlorobenzophenone (4.1 g) and triethylamine (3.65 g) in dioxane (80 cc) which is heated to a temperature in the vicinity of 60° C., in the course of 15 minutes. The suspension obtained is heated, with stirring, at a temperature in the vicinity of 100° C. for 5 hours and 40 minutes and then stirred at a temperature in the vicinity of 20° C. for 16 hours. The solvent is evaporated off under reduced pressure (20 mm Hg; 2.7 kPa) at a temperature in the vicinity of 50° C. The residue is dissolved in methylene chloride (250 cc). The solution obtained is washed twice with distilled water (200 cc in total), with an aqueous 2N sodium hydroxide solution (100 cc) and then 3 times with distilled water (300 cc in total) and then dried over anhydrous magnesium sulphate, treated with decolourizing charcoal (0.5 g), filtered and concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at a temperature in the vicinity of 45° C. A crude product (8.3 g) is thereby obtained, which is dissolved in boiling acetonitrile (50 cc). Decolourizing charcoal (0.5 g) is added to the solution obtained and the suspension is filtered in the heated state. The filtrate is cooled at a temperature in the vicinity of 4° C. for 1 hour. The crystals formed are separated by filtration, washed twice with acetonitrile cooled to a temperature in the vicinity of 4° C. (30 cc in total) and twice with diethyl ether (60 cc in total) and then dried under reduced pressure (20 mm Hg; 2.7 kPa) at a temperature in the vicinity of 20° C. in the presence of potassium hydroxide pellets. (+)-N-(2-chloro-5-benzoylphenyl)-3- pyridyl)-1H,3H-pyrrolo[1,2-c]thiazole-7-carboxamide (3.7 g) in the form of cream-coloured crystals, m.p. 154° C., is thereby obtained.

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