4-Hydroxy-but-2-ynoic acid ethyl ester → 1-Hydroxymethyl-5H-pyrimido[2,1-c][1,4] benzoxazin-3-one

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Reaction Steps

A solution of the compound of formula II, 3-amino-2H-1,4-benzoxazine (10.7 g, 72.1 mmol, described in Example 3) and hydroxymethylacetylenecarboxylate ethyl ester (9.7 g, 75.7 mmol) in ethanol (100 ml) was allowed to stand at room temperature (20° to 24° C.) for 6 days. The resulting precipitate was collected giving 12.03 g of the title compound as tan crystals with mp 235°-237° L C., the mp remaining unchanged or recrystallization from ethanol. The title compound had IR(nujol)3130, 1640 cm-1 ; NMR(Trifluoroacetic acid)δ5.2 (s,2H); 5.3(s,2H); 7.6(m,5H); Anal. Calc'd: C, 62.60%; H, 4.38%; N, 12.17%; Found: C, 62.32%; H, 4.24%; N, 12.17%.

Provenance & Evidence