Processes for the production of n-substituted sulfoximine pyridine n-oxides

A process for preparing an N-oxidized sulfoximine compound of formula (I)

• wherein
• X represents NO2, CN, COOR4 or CONH2;
• L represents a single bond or R1, S and L taken together represent a 4-, 5- or 6-membered ring;
• R2 represents (C1-C4) alkyl;
• R2 and R3 individually represent hydrogen, methyl, ethyl, flouro, chloro or bromo;
• n is an integer from 0-3;
• Y represents (C1-C4) haloalkyl, F, Cl, Br, or I;
• and
• R4 represents (C1-C3) alkyl;
• which includes performing an oxidation of a compound of formula (II)
• wherein X, L, R1, R2, R3, n, Y and R4 are as previously defined and the oxidation includes treating the compound of formula (II) with urea hydrogen peroxide and trifluoroacetic anhydride.