[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][C:14](=O)[C:13]([CH3:19])([CH3:18])[CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C([O-])(=O)C.[NH4+].C([BH3-])#[N:26].[Na+]>CO>[NH2:26][CH:14]1[CH2:15][CH2:16][N:11]([C:9]([O:8][CH2:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)=[O:10])[CH2:12][C:13]1([CH3:19])[CH3:18]1-Benzyloxycarbonyl-3,3-dimethyl-4-piperidone (290 g, 1.11 mol) was dissolved in methanol (1.5 L) and under stirring addition of ammonium acetate (600 g, 7.80 mol ) was made at 30-35° C. The reaction mixture was stirred for 5 hrs. Sodium cyanoborohydride (35 g, 0.55 mol) was added portion wise to the suspension. over 0.5 hrs by maintaining temperature between 0-10° C. The reaction mixture was stirred for 6-7 hrs. After completion of reaction, solvent was evaporated under reduced pressure and addition of 3.00 L water was made under stirring. The reaction mixture was stirred for 15 minutes. It was extracted with 1.5 L×2 CHCl3. Combined organic extract was evaporated under vacuum. The residue was dissolved in 3 N HCl till pH 1 and was extracted with 500 ml×2 dichloromethane. The aqueous layer was basified with 300 ml aqueous ammonia solution (23-25%) to pH 10-11 and then was extracted with 1.5 L×3 dichloromethane. Combined organic extract was washed with water and was dried over sodium sulfate. Evaporation of organic solvent afforded 225 g (77%) title compound.
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