Patent ID: 7205415

Claim:
A process for the preparation of simvastatin of formula I: which comprises the steps of: a) reacting compound of formula II (lovastatin): with the compound of formula IV: HNR 1 R 2 IV wherein R 1 is —R 5 —X—R 6 wherein R 5 is alkyl, arylalkyl or cycloalkyl, X is O or S and R 6 is alkyl, arylalkyl, cycloalkyl or aryl; and R 2 is H; to produce a compound of formula V: wherein R 1 and R2 are as defined above, (b) optionally protecting the two hydroxyl groups of the compound of the formula V to produce a compound of the formula VI: wherein R3 and R4 represents suitable protecting groups, (c) methylating said compound of formula V or VI to give a compound of formula VIIa or VIIb: wherein R 1 , R 2 , R 3 and R 4 are as defined above, (d) hydrolyzing the amide group if the product of the above step is said compound of formula VIIa or deprotecting the two protected hydroxy groups prior to hydrolysis if the product of the above step is said compound of formula VIIb, optionally treating the hydrolyzed product with aqueous ammonia, to produce a compound of formula VIII: wherein M′ is a metal such as sodium or potassium or NH 4 , and (e) lactonizing said compound of the formula VIII to produce simvastatin of formula I.