Reaction #657280

Reaction equation

4-benzyloxy-1-cyclopropylmethyl-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-2-one

→

1-cyclopropylmethyl-4-hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-2-one

Solvents

methanol

Conditions

Workup

1. 1
   Othera temperature of 35° C.
2. 2
   ConcentrationThe collected product solution was concentrated
3. 3
   Otherthe residue purified by chromatography on silica gel (ethyl acetate/heptane 1:1)

Procedure

Debenzylation was conducted using an H-Cube® continuous-flow hydrogenator: 4-benzyloxy-1-cyclopropylmethyl-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-2-one (546 mg, 1.34 mmol) was dissolved in methanol (47 ml) and this substrate solution (0.029 M) pumped twice through a 5% Pd/C filled cartridge at a flow-rate of 1 mL/min, a temperature of 35° C. and a pressure of 2-3 bars. The collected product solution was concentrated, and the residue purified by chromatography on silica gel (ethyl acetate/heptane 1:1). Yield: 215 mg of 1-cyclopropylmethyl-4-hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-2-one (title compound P2.8) as a white solid, mp 223-225° C.

Source