methyl 2-dimethoxyphosphoryl-2-[(2-methylpropan-2-yl)oxycarbonylamino]acetate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxine-6-carbaldehyde (5.0 g) was dissolved in 25 mL dry DCM under nitrogen at rt and 3.6 mL DBU was added by syringe. 3.8 g of Boc-phosphonoglycine trimethyl ester in 10 mL dry DCM was added by syringe dropwise and the mixture stirred at rt for 14 hours. The residue was purified over silica (hexanes to 8:2 hexanes/EtOAc) 4.9 g desired product after drying under vacuum. 1H NMR (400 MHz, CDCl3): 7.54 (d, 1H), 7.46 (d, 1H), 7.35 (m, 2H), 7.27 (m, 1H), 7.22-7.19 (m, 2H), 7.11 (m, 1H), 6.98 (m, 2H), 6.93 (d, 1H), 5.10 (m, 1H), 5.04 (s, 2H), 4.32 (m, 1H), 4.02 (m, 1H), 3.84 (s, 3H), 1.44 (s, 9H). The residue was purified over silica (hexanes to 8:2 hexanes/EtOAc) 4.9 g desired product after drying under vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (S)-2-[3-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxine-6 carbaldehyde (2.1 g) was dissolved in 8 mL dry DCM under nitrogen at rt and DBU (1.61 g) was added by syringe. A solution of Boc-phosphonoglycine trimethyl ester (1.58 g) in 4 mL of dry DCM was added to the reaction mixture and stirred at rt. for 12 hours. Reaction mixture was directly loaded on to silica gel column (40% hexanes in DCM to DCM) gave 1.8 g pure product. 1H NMR (400 MHz, CDCl3): 7.55 (d, 1H), 7.46 (d, 1H), 7.32-7.38 (m, 1H), 7.18-7.28 (m, 3H), 7.10-7.15 (m, 1H), 6.94-7.06 (m, 4H), 5.13 (m, 1H), 5.03 (s, 2H), 4.36 (m, 1H), 4.01 (m, 1H), 3.84 (s, 3H), 1.44 (s, 9H). LCMS (m/z): 587. Reaction mixture

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (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). extracted the organic layer was dried with brine and Na2SO4 evaporated The residue was purified by crystallization from EtOAc/hexanes

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxine-6-carbaldehyde (5.0 g) was dissolved in 25 mL dry DCM under nitrogen at rt and 3.6 mL DBU was added by syringe. 3.8 g of Boc-phosphonoglycine trimethyl ester in 10 mL dry DCM was added by syringe dropwise and the mixture stirred at rt for 14 hours. The residue was purified over silica (hexanes to 8:2 hexanes/EtOAc) 4.9 g desired product after drying under vacuum. 1H NMR (400 MHz, CDCl3): 7.54 (d, 1H), 7.46 (d, 1H), 7.35 (m, 2H), 7.27 (m, 1H), 7.22-7.19 (m, 2H), 7.11 (m, 1H), 6.98 (m, 2H), 6.93 (d, 1H), 5.10 (m, 1H), 5.04 (s, 2H), 4.32 (m, 1H), 4.02 (m, 1H), 3.84 (s, 3H), 1.44 (s, 9H). The residue was purified over silica (hexanes to 8:2 hexanes/EtOAc) 4.9 g desired product after drying under vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (S)-2-[3-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxine-6 carbaldehyde (2.1 g) was dissolved in 8 mL dry DCM under nitrogen at rt and DBU (1.61 g) was added by syringe. A solution of Boc-phosphonoglycine trimethyl ester (1.58 g) in 4 mL of dry DCM was added to the reaction mixture and stirred at rt. for 12 hours. Reaction mixture was directly loaded on to silica gel column (40% hexanes in DCM to DCM) gave 1.8 g pure product. 1H NMR (400 MHz, CDCl3): 7.55 (d, 1H), 7.46 (d, 1H), 7.32-7.38 (m, 1H), 7.18-7.28 (m, 3H), 7.10-7.15 (m, 1H), 6.94-7.06 (m, 4H), 5.13 (m, 1H), 5.03 (s, 2H), 4.36 (m, 1H), 4.01 (m, 1H), 3.84 (s, 3H), 1.44 (s, 9H). LCMS (m/z): 587. Reaction mixture

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (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). extracted the organic layer was dried with brine and Na2SO4 evaporated The residue was purified by crystallization from EtOAc/hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl [(tert-butoxycarbonyl)amino](dimethoxyphosphoryl)acetate (3.53 g, 11.9 mmol) in methylene chloride (180 mL) was treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (1.92 mL, 12.9 mmol). After five minutes 4-(2-tert-butyl-1,1-dioxido-3-oxoisothiazolidin-5-yl)-3-fluorobenzaldehyde (3.1 g, 9.9 mmol) was added and the solution stirred at rt for 1 h. The solution was diluted with methylene chloride (50 mL), washed with 1 N aqueous hydrochloric acid solution (250 mL), and the organic phase dried over sodium sulfate. Purification by silica gel chromatography (5–25% ethyl acetate:hexanes) afforded product as a white foam (3.7 g, 77%). 1H NMR (400 MHz, CDCl3): δ 7.35–7.29 (m, 3H), 7.17 (s, 1H), 5.04 (dd, J=9.0, 7.1 Hz, 1H), 3.87 (s, 3H), 3.29 (dd, J=17.2, 9.0 Hz, 1H), 3.17 (dd, J=17.2, 7.0 Hz, 1H), 1.65 (s, 9H), 1.39 (s, 9H). LCMS found for C22H30FN2NaO7S (M+Na)+: m/z=507. washed with 1 N aqueous hydrochloric acid solution (250 mL) the organic phase dried over sodium sulfate Purification by silica gel chromatography (5–25% ethyl acetate:hexanes)