Ethyl pyrrolo[1,2-c]pyrimidine-3-carboxylate

Synthesis

General procedure for the synthesis of ethyl pyrrolo[1,2-c]pyrimidine-3-carboxylate from 2-pyrrole carboxaldehyde and ethyl isocyanoacetate: to a solution of 1H-pyrrole-2-carboxaldehyde (9.51 g, 100.0 mmol, 1.0 eq.) in dichloromethane (DCM, 150.0 mL) was added 1,8-diazadicyclohexadec-7-ene (DBU, 15.2 g, 100.0 mmol, 1.0 eq.). 100.0 mmol, 1.0 equiv) followed by ethyl isocyanoacetate (11.3 g, 100.0 mmol, 1.0 equiv). The reaction mixture was heated to reflux and maintained for 3 hours. Upon completion of the reaction, the reaction was quenched by the addition of 10% aqueous acetic acid (250 mL) and the organic phase was separated. The organic phase was washed sequentially with water (100 mL x 2), dried over anhydrous magnesium sulfate (MgSO), filtered and concentrated. The residue was purified by column chromatography (petroleum ether/ethyl acetate=4/1, v/v) to afford the target product ethyl pyrrolo[1,2-c]pyrimidine-3-carboxylate as a yellow solid (18.5 g, 97.3% yield).

References

[1] Patent: WO2018/35061, 2018, A1. Location in patent: Paragraph 0448
[2] Organic and Biomolecular Chemistry, 2015, vol. 13, # 14, p. 4231 - 4239
[3] Patent: US2003/236264, 2003, A1. Location in patent: Page 49
[4] Tetrahedron Letters, 1996, vol. 37, # 24, p. 4263 - 4266