5-Chloro-2-ethoxyphenylboronic acid → tert-butyl 5-(5-chloro-2-ethoxyphenyl)-2H-1,4-oxazine-4(3H)-carboxylate

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Reaction Steps

This compound was prepared from tert-butyl 5-((diphenoxyphosphoryl)oxy)-2H-1,4-oxazine-4(3H)-carboxylate and 5-chloro-2-ethoxyphenylboronic acid using a procedure similar to that described in Example 2 (Steps 1-3a) above. The product was isolated as a white solid (24% yield); 1H-NMR (d6-DMSO) 1.05 (9H, brs), 1.26 (3H, t), 3.62 (2H, t), 3.92 (2H, q), 4.15 (2H, t), 6.21 (1H, s), 6.90 (1H, d), 7.09 (1H, m), 7.22 (1H, dd); 13C-NMR (d6-DMSO) 14.9, 27.7, 63.9, 67.05, 67.1, 111.9, 126.9, 127.3, 132.0; MS ES(+) 240.0 (M++1); Anal. Calcd for C17H22ClNO4: C, 60.09; H, 6.53; N, 4.12. Found: C, 59.60; H, 6.46; N, 4.35. IR λmax=1701, 1394 cm−1.

Provenance & Evidence