Acetic Acid → 8-(3-Ethoxy-4-methyl-benzyl)-1,3,8-triaza-spiro[4.5]decane-2,4-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 1,3,8-triaza-spiro[4.5]decane-2,4-dione (25.4 mg, 0.15 mmol, 1.0 equiv; intermediate A1) in ethanol (1 mL), acetic acid (72.1 mg, 1.2 mmol, 8.0 equiv) and N-ethyl diisopropylamine (77.6 mg, 0.6 mmol, 4.0 equiv) was added 3-ethoxy-4-methyl-benzaldehyde (29.6 mg, 0.18 mmol, 1.2 equiv; intermediate B10, vide infra) and the mixture stirred at 55° C. After 1 h, sodium cyanoborohydride (47.1 mg, 0.75 mmol, 5.0 equiv), dissolved in ethanol (0.5 mL), was added and the mixture stirred at 55° C. over night. Removal of the solvent under reduced pressure and purification by preparative HPLC on reversed phase eluting with a gradient of acetonitrile/water provided 8.6 mg (17%) of the title compound. MS (ISP): 338.2 [M+H]+.

Provenance & Evidence