Reaction #657282

Reaction equation

HCl

ammonium chloride

1-methoxy-4-{methyl-[2-(2,4,6-trimethyl-phenyl)-acetyl]-amino}-piperidine-4-carboxylic acid methyl ester

sodium methoxide

→

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

Solvents

dimethylformamide

Conditions

Workup

1. 1
   workup.WAITat room temperature for 1 hour
2. 2
   Extractionthoroughly extracted with ethyl acetate
3. 3
   WashThe combined organic layers were washed with water and brine
4. 4
   Dryingdried over sodium sulfate
5. 5
   Concentrationconcentrated
6. 6
   Otherthe residue dried in vacuo

Procedure

To a solution of 1-methoxy-4-{methyl-[2-(2,4,6-trimethyl-phenyl)-acetyl]-amino}-piperidine-4-carboxylic acid methyl ester (85.0 g, 234.5 mmol) in dimethylformamide (800 ml) at 0° C. was added sodium methoxide (38.0 g, 703.5 mmol) in four portions and stirring continued at 0° C. for 30 minutes, then at room temperature for 1 hour. The reaction mixture was poured on ice and saturated aqueous ammonium chloride, acidified to pH 5-6 with concentrated HCl and thoroughly extracted with ethyl acetate. The combined organic layers were washed with water and brine, dried over sodium sulfate, concentrated and the residue dried in vacuo. Yield: 72.7 g of 4-hydroxy-8-methoxy-1-methyl-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-2-one (title compound P2.2) as a solid.

Source