Formamide → HCID 178461168, Verbindung

Temperatur

150 °C

A solution containing (R)-ethyl 2-amino-5-methylcyclopent-1-enecarboxylate (161.61 g, 955.024 mmol) and ammonium formate (90.3298 g, 1432.54 mmol) in formamide (303.456 mL, 7640.19 mmol) was heated to an internal temperature of 150° C. and stirred for 17 hours. The reaction mixture was cooled and transferred to a 2L single nextracted flask. The 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 portions were extracted with DCM (1×). The combined organic extracts were dried (Na2SO4), filtered, and concentrated. The resulting brown oil was dissolved in minimal DCM, and this solution was added using a separatory funnel to a stirred solution of ether (ca. 5 volumes of ether vs. DCM solution). This caused some brown precipitate to form. This brown precipitate was removed by filtration through a medium frit funnel, which was rinsed with ether and disposed. The filtrate was concentrated. The trituration from ether repeated two more times and then dried on high vacuum line to give (R)-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-ol (93.225 g, 65.00% yield) as a brown-yellow pasty solid. LC/MS (APCI−) m/z 149.2.