Diethyl squarate → 3-{[4-(4-Amino-6-ethylthieno[2,3-d]pyrimidin-5-yl)phenyl]amino}-4-ethoxy-3-cyclobutene-1,2-dione

Participants

Reaction Steps

A mixture of Example 78A (0.135 g, 0.5 mmol) and 3,4-diethoxy-3-cyclobutene-1,2-dione (0.22 mL, 1.5 mmol) in ethanol (5 mL) was heated at 70-80° C. for 48 hours, then filtered while still hot. The filtrate was concentrated and the resulting residue was washed with hexanes and diethyl ether, and dried to provide 0.11 g of the desired product. MS (ESI(+)) m/e 395 (M+H)+.

Provenance & Evidence