1,8-Diazabicyclo(5.4.0)undec-7-ene → 2-Tert-butoxycarbonylamino-3-{(s)-2-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxin-6-yl}-acrylic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

(S)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxine-6-carbaldehyde (9.9 g) was dissolved in 80 mL dry DCM under nitrogen at rt and 7.2 mL DBU (7.33 g) was added by syringe. 7.44 g of Boc-phosphonoglycine trimethyl ester in 40 mL dry DCM was added by syringe all at once and the mixture stirred at rt for 18 h. It was then diluted with 0.5 L each of DCM and water and extracted, and the organic layer was dried with brine and Na2SO4 and evaporated. The residue was purified by crystallization from EtOAc/hexanes to give 12 g desired product after drying under vacuum. 1H NMR (400 MHz, CDCl3): 7.54 (d, 1H), 7.46 (d, 1H), 7.34 (m, 2H), 7.28-7.24 (m, 1H), 7.23-7.17 (m, 2H), 7.11 (m, 1H), 6.98 (m, 2H), 6.93 (d, 1H), 5.10 (m, 1H), 5.03 (s, 2H), 4.32 (m, 1H), 4.01 (m, 1H), 3.84 (s, 3H), 1.44 (s, 9H).

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