7-Chloropyrazolo[1,5-a]pyrimidin-5-amine → Methyl 4-(7-chloro-2-cyclopropylpyrazolo[1,5-a]pyrimidin-5-ylcarbamoyl)benzoate

関与物質

反応条件

反応手順

7-Chloropyrazolo[1,5-a]pyrimidin-5-amine (1E, 1.0 equivalent), 7-chloro-2-methylpyrazolo[1,5-a]pyrimidin-5-amine (1J, 1.0 equivalent), 7-chloro-2-ethylpyrazolo[1,5-a]pyrimidin-5-amine (1O, 1.0 equivalent), or 7-chloro-2-cyclopropylpyrazolo[1,5-a]pyrimidin-5-amine (1S, 1.0 equivalent) was suspended in pyridine (0.3 M). At 0° C. was added terephthalic acid monomethylester chloride (2B, 1.3 equivalents), and the mixture was stirred vigorously at 0° C. for 4-18 h. The reaction was quenched with saturated NaHCO3 and stirred for another 0.5 h; pyridine was removed in vacuo and the residue was suspended in water. The precipitate was collected on a fritted glass funnel and was washed twice with water. After drying under a stream of N2 for 15 h, the crude product methyl 4-(7-chloropyrazolo[1,5-a]pyrimidin-5-ylcarbamoyl)benzoate 2C (92%), methyl 4-(7-chloro-2-methylpyrazolo[1,5-a]pyrimidin-5-ylcarbamoyl)benzoate 2E (72%), methyl 4-(7-chloro-2-ethylpyrazolo[1,5-a]pyrimidin-5-ylcarbamoyl)benzoate 2G (84%) or methyl 4-(7-chloro-2-cyclopropylpyrazolo[1,5-a]pyrimidin-5-ylcarbamoyl)benzoate 2I (98%) was obtained as an orange solid and was used without further purification.

情報源と証拠