反应详情

温度

150 °C

A solution containing (R)-ethyl 2-amino-5-methylcyclopent-1-enecarboxylate (161.6 g, 955 mmol) and ammonium formate (90.3 g, 1433 mmol) in formamide (303.5 mL, 7640 mmol) was heated to an internal temperature of 150° C. and stirred for 17 hours. The reaction mixture was cooled, and transferred to a 2 L single nextracted flask. Then excess formamidine was removed by high vacuum distillation. Once formamidine stopped coming over, the remaining oil in the still pot was dissolved in DCM and washed with brine (3×200 mL). The combined aqueous washes were extracted with DCM. The combined organic extracts were dried (Na2SO4), filtered, and concentrated. The resulting oil was dissolved in minimal DCM, and this solution was added using a separatory funnel to a stirred solution of ether (about 5 volumes of ether vs. DCM solution), causing some precipitate to form. This precipitate was removed by filtration through a medium frit funnel that was rinsed with ether and disposed. The filtrate was concentrated, and the trituration from ether repeated two more times. The product was then dried on a high vacuum line to give (R)-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-ol (93.23 g, 65.0% yield) as a pasty solid. LC/MS (APCI−) m/z 149.2.

1. temperatureThe reaction mixture was cooled
2. customtransferred to a 2 L single nextracted flask
3. customThen excess formamidine was removed by high vacuum distillation
4. dissolutionpot was dissolved in DCM
5. washwashed with brine (3×200 mL)
6. extractionThe combined aqueous washes were extracted with DCM
7. dry with materialThe combined organic extracts were dried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated
10. dissolutionThe resulting oil was dissolved in minimal DCM
11. additionthis solution was added
12. customto form
13. customThis precipitate was removed by filtration through a medium frit funnel that
14. washwas rinsed with ether
15. concentrationThe filtrate was concentrated
16. customThe product was then dried on a high vacuum line