Hydrochloric Acid → (2S)-7-hydroxy-2-methyl-2-(trifluoromethyl)-2,3-dihydroimidazo[1,2-a]pyrimidin-5(1H)-one

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Reaction Steps

36.90 g (148.76 mmol) of (S)-4-methyl-4-trifluoromethyl-4,5-dihydro-1H-imidazol-2-ylamine hydrobromide and 24.10 g (446 mmol) of sodium methoxide are added to a mixture of 29.50 g (216.43 mmol) of diethyl malonate in 200 mL of methanol. The resulting mixture is refluxed for 18 hours. After cooling, the mixture obtained is concentrated to dryness under vacuum. 65 mL of cold water are added to the residue obtained, to obtain a thick suspension, to which is added 25% hydrochloric acid to pH 5. The resulting suspension is stirred in an ice bath for 3 hours and then filtered. The insoluble matter obtained is rinsed with water and then dried to give 37.60 g of (S)-7-hydroxy-2-methyl-2-trifluoromethyl-2,3-dihydro-1H-imidazo[1,2-a]pyrimidin-5-one in the form of a white solid, the characteristics of which are as follows:

Provenance & Evidence