4-Carboxyphenylboronic Acid → 4-(4-(tert-butoxycarbonyl)-3,4-dihydro-2H-1,4-oxazin-5-yl)benzoic acid

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Reaction Steps

This compound was prepared from tert-butyl 5-((diphenoxyphosphoryl)oxy)-2H-1,4-oxazine-4(3H)-carboxylate and 4-boronobenzoic acid using a procedure similar to that described in Example 2 (Steps 1-3a) above. The product was isolated as an off-white solid (30% yield); 1H-NMR (d6-DMSO) 1.06 (9H, s), 3.69 (2H, t), 4.12 (2H, t), 6.58 (1H, s), 7.29 (2H, d), 7.85 (2H, d), 12.83 (1H, brs); 13C-NMR (CDCl3); 27.7, 41.3, 66.8, 124.5, 130.1, 134.0; MS ES(+) 249.9 (M+-tBu). IR λmax=1701, 1674 cm−1.

Provenance & Evidence