Paliperidone Impurity 7 synthesis

Yield:1415488-05-9 95%

Reaction Conditions:

Stage #1: 3-(2-chloroethyl)-9-hydroxy-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one;1-hexadecylcarboxylic acidwith dmap;triethylamine in dichloromethane at 25 - 30; for 0.25 h;
Stage #2: with pivaloyl chloride in dichloromethane at 25 - 40; for 2 h;

Steps:

1

A mixture of methylene chloride, 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2- methyl-9-hydroxy-4H-pyrido[ l ,2-a] pyrimidine-4-one, palmitic acid , 4-dimethyl amino pyridine and triethylamine was stirred for 15 min at 25-30 C, pivaloyl ^' chloride was added slowly to above reaction mass at 25-40 °C and the reaction was maintained for 2 hours at 30-35 ^°C then the reaction mass was cooled to 25 °C, charged purified water, separated the organic layer, washed the organic layer with dilute hydrochloric acid followed by water, distilled off methylene chloride completely and co distilled with acetonitrile. The resulted residue was dissolved in acetonitrile and added purified water slowly at 25-30 °C, stirred the contents for 30 minutes at the same temperature and cooled the mass to 10-15 °C stirred for 2 hours at the same temperature, filtered the isolated compound, washed the wet cake with chilled acetonitrile and dried the compound under vacuum.Yield: 95% (Theoretical).

References:

WO2012/164582,2012,A1 Location in patent:Page/Page column 10-11