Ethanol → ethyl 5-oxo-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate

Participants

Reaction Steps

A solution of 2-aminothiazole (10g., 100mM) and diethyl ethoxymethylenemalonate (21.6g., 100mM) in 1,2,4-trichlorobenzene (100ml) was heated at 150° C for 4 hours with collection of evolved ethanol. The reaction mixture was cooled and the required product filtered off and recrystallised from ethanol in 75.9% weight yield (17.0g). δ (CDCl3), 8.98 (1H,s, H5), 8.33 (1H,d, H1, J = 5.0Hz), 7.40 (1H,d, H2, J = 5.0Hz), 4.47 (2H,q, --CH2CH3), 1.41 (3H,t, --CH2CH3); λmax (MeOH) 235nm (εm 5000), 258nm (εm 4,550) and 346nm (εm 13,500); (Found: C, 47.84; H, 3,42; N, 12.19; S, 14.54%. C9H8N2O3S requires C, 48.22; H, 3.60; N, 12.50; S, 14.28%).

Provenance & Evidence