Patent ID: 6489482
Filing Date: 2002-12-03
Classification: C07D

Abstract:
A process for the preparation of a vinylic hindered amine light stabilizer of formula (1) whereinR1 is linear or branched C1 to C8 alkyl, alkoxy, alkylphenyl or hydroxy alkyl, or R1 is allyl, acyl, or cycloalkyl; R2 is hydrogen or methyl; R3 is vinyl or C1-4 alkyl vinyl; R4 is hydrogen, C1-4 alkyl or alkyl phenyl; R5 is hydrogen or C1-4 alkyl; and X is O, NH, C1-8 linear or branched chain or alkylamino comprising refluxing a solution of a compound of formula II wherein R2, R5 and X are as defined above, in an organic solvent containing a carbonyl compound of the Formula IIIR1COR6â€ƒâ€ƒ(Formula III) wherein R1 is as defined above and R6 is linear or branched C1 to C8 alkyl, alkoxy, alkylphenyl or hydroxy alkyl, or R1 is allyl, acyl, or cycloalkyl for a period of from four to six hours, adjusting the pH into the range 7.0 to 9.0, extracting the reaction product in an organic solvent to obtain a compound of Formula IV and thereafter contacting said compound of Formula IV with an alkyl-substituted aminopyridine or 2-mercaptobezoxazole catalyst in a dry organic solvent and reacting it with a compound of Formula VCH2&boxH;C(R)â€”C(O)â€”Cl wherein R is hydrogen, C1-4 alkyl or alkylphenyl in an inert atmosphere in the presence of an organic base and thereafter continuing the reaction with stirring for from 8 to 12 hours and then quenching with water to a temperature of from 0 to 4Â° C. and extracting the product by solvent extraction with an organic solvent and neutralizing the extract with an inorganic base and removing the solvent to obtain a compound of Formula I.