Diethyl Carbonate → tert-butyl 7-(2-ethoxy-2-oxoethyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

The compound was prepared according to the procedure as described in WO 0033838. To a solution of 2-methyl-8-(tert-butoxycarbonyl)-5,6,7,8-tetrahydro-1,8-naphthyridine (1.4 g, 5.6 mmol) and diethylcarbonate (2.5 g, 20 mmol) in THF (10 ml) was added LDA (8 ml of 2M solution in hexane) at −78° C. and stirred at −78° C. for 40 minutes. The reaction was quenched with saturated NH4Cl and extracted with ethylacetate (2×100 ml). Combined organic solution was concentrated and purified on silica gel column to give 1.5 g (83%) yellow oil. NMR (CD3OD) δ 1.25 (t, 3H, J=7.10 Hz), 1.51 (s, 9H), 1.88-1.97 (m, 2H), 2.75 (t, 2H, J=6.59 Hz), 3.74-3.80 (m, 4H), 4.10-4.20 (m, 2H), 7.0 (d, 1H, J=7.61Hz), 7.39 (d, 1H, J=7.47 Hz).

Provenance & Evidence