Potassium Phosphate, Dibasic → Benzyl ((2R,3S)-2-((5-methyl-2H-tetrazol-2-yl)methyl)-4-oxoazetidin-3-yl)carbamate

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Reaction Steps

Prepared in an analogous manner to example 4, step 2 using benzyl ((2R,3S)-1-(2,4-dimethoxybenzyl)-2-((5-methyl-2H-tetrazol-1-yl)methyl)-4-oxoazetidin-3-yl)carbamate (202 mg, 0.433 mmol), K2S2O8 (164 mg, 0.606 mmol) and K2HPO4 (98 mg, 0.563 mmol) in ACN:water (2:1, 7.4 mL) at 90° C. for 1.5 h. More K2S2O8 (35 mg, 0.13 mmol) and K2HPO4 (20 mg, 0.11 mmol) were added and it was heated for an additional 30 min then cooled to rt then concentrated in vacuo. The mixture was diluted with EtOAc, washed with brine, dried over Na2SO4 and concentrated in vacuo. The crude residue was purified via silica gel chromatography (MeOH-DCM, 0-10%), to afford the title compound (111 mg, 81%). LCMS: Rt=0.58 min, m/z=317.2 (M+1) Method 2m_acidic; 1H NMR (400 MHz, CDCl3) δ 7.43-7.30 (m, 5H), 6.34 (br s, 1H), 6.01 (br s, 1H), 5.28-5.21 (m, 1H), 5.20-5.12 (m, 3H), 4.92 (dd, J=14.3, 3.9 Hz, 1H), 4.68 (dd, J=14.2, 7.9 Hz, 1H), 4.48-4.27 (m, 2H), 2.53 (s, 3H).

Provenance & Evidence