Urea → Ethyl 2-amino-4-methyl-1,3-oxazole-5-carboxylate

関与物質

反応条件

反応手順

Ethyl 2-chloroacetoacetate (8.0 mL, 59 mmol) was added to a mixture of urea (10.6 g, 176 mmol) in MeOH (40 mL), and the reaction mixture was heated to 66° C. overnight. Upon cooling to room temperature, the solids were collected by filtration and suspended in 1 N aqueous NaOH (50 mL). This was extracted with EtOAc (100 mL). The aqueous layer was brought to pH ˜11 with NaOH and was extracted with EtOAc (3×100 mL). The EtOAc extracts were combined, dried over Na2SO4, filtered, and concentrated under reduced pressure. This gave 5.02 g (50%) of the title compound as a white solid. LC-MS: RT=5.1 min, [M+H]+=171.

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