Cyclopentylamine → 4-Cyclopentylamino-8-methoxy-quinoline-3-carboxylic acid ethyl ester

Participants

Reaction Steps

4-Chloro-8-methoxy-quinoline-3-carboxylic acid ethyl ester (2.65 g, 10.0 mmol) was treated with cyclopentylamine (1.06 g, 1.2 eq. 12.0 mmol) following a method similar to general procedure B to afford 4-cyclopentylamino-8-methoxy-quinoline-3-carboxylic acid ethyl ester (2.9 g). The obtained amino-ester (0.5 mmol) was subjected to reaction with ethyl isocyanate (2.0 mmol) according to general procedure C to furnish 1-cyclopentyl-3-ethyl-7-methoxy-1H-pyrimido[5,4-c]quinoline-2,4-dione (83 mg). LCMS: m/z 340 [M+1]+. 1H NMR (400 MHz, CDCl3): δ 9.43 (s, 1H), 7.78 (d, 1H), 7.55 (t, 1H), 7.20 (d, 1H), 4.99 (p, 1H), 4.13 (s, 3H), 4.11 (q, 2H), 2.42 (m, 2H), 2.06 (m, 4H), 1.62 (m, 2H) and 1.32 (t, 3H) ppm.

Provenance & Evidence