Methods of making amidino compounds useful as nitric oxide synthase inhibitors

A method for the preparation of a hydantoin compound having the structure of Formula 35:

• 106
• or a salt, an enantiomer, or a racemate thereof,
• wherein:
• R2 is selected from the group consisting of C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C5 alkoxy-C1 alkyl, and C1-C5 alkylthio-C1 alkyl;
• R1, R5, R6, and R7 independently are selected from the group consisting of —H, halogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, and C1-C5 alkoxy-C1 alkyl;
• R9 and R10 independently are selected from the group consisting of —H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, and C1-C5 alkoxy-C1 alkyl;
• and
• when any of R1, R2, R5, R6, R7, R9, and R10 independently is a moiety selected from the group consisting of alkyl, alkenyl, and alkynyl, then the moiety is optionally substituted by one or more substituent selected from the group consisting of —OH, alkoxy, and halogen;
• wherein the method comprises contacting an alpha-sulfo ketone compound having the structure of Formula 36:
• 107
• with a source of cyanide in the presence of a source of ammonium carbonate and water, thereby producing the hydantoin compound.