Sodium Methoxide → Tert-butyl 10-(methoxymethyl)-8-pyrimidin-2-yl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate

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Reaction Steps

Tert-butyl 4-(pyrimidin-2-yl)-2-(tosyloxymethyl)-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate (1.83 g, 3.53 mmol) was dissolved in a solution of sodium methoxide (71 mL of 0.5 M in methanol, 35 mmol) and refluxed for 18 h. The solvent was evaporated to dryness and the residue dissolved in dichloromethane (200 mL). The solution was washed with water and brine, dried over Na2SO4, filtered and concentrated in vacuo. Silica gel chromatography (5-80% ethyl acetate/hexanes) provided tert-butyl 10-(methoxymethyl)-8-pyrimidin-2-yl-11-oxa-3,8-diazaspiro[5.5]undecane-3-carboxylate as colorless oil. ESI-MS m/z calc. 378.2. found 379.3 (M+1)+; Retention time: 1.54 minutes (3 min run). 1H NMR (400 MHz, MeOD) δ 8.31 (d, J=4.8 Hz, 2H), 6.58 (t, J=4.8 Hz, 1H), 4.72-4.52 (m, 2H), 3.91 (ddd, J=10.9, 7.9, 4.9 Hz, 1H), 3.76-3.59 (m, 2H), 3.56-3.44 (m, 2H), 3.40 (s, 3H), 3.13 (t, J=11.1 Hz, 1H), 2.85-2.65 (m, 2H), 1.98 (d, J=14.6 Hz, 2H), 1.59 (dd, J=8.7, 4.5 Hz, 2H), 1.45 (s, 9H), 1.44-1.37 (m, 1H).

Provenance & Evidence