Process to prepare (5R)-(methylamino)-5, 6-dihydro-4H-imidazo[4,5,1-ij]-quinolin-2(1H)-one

A process for the preparation of a tetracyclic compound of formula (VI)

• where RN is selected from the group consisting of:
• (A) φ-CH2— where phenyl is optionally substituted with 1 or 2:
• (1) C1-C4 alkoxy,
• (2) F—,
• (3) Cl—,
• (4) Br—,
• (5) I—,
• (6) C1-C4 alkyl,
• (B) RN1—CH2—O—CH2 where RN1 is selected from the group consisting of:
• (1) φ-optionally substituted with:
• (a) C1-C4 alkyl,
• (b) F—,
• (c) Cl—,
• (d) Br—,
• (e) I—,
• (f) C1-C4 alkoxy,
• (2) (CH3)3Si—CH2—,
• (3) RN2—O—CH2— where RN2 is C1-C4 alkyl,
• (4) CH2═CH—,
• (5) —H,
• (6) C1-C4 alkyl;
• (C) an unsaturated compound selected from the group consisting of:
• (1) CH2═CH—CH2—,
• (2) CH3—CH═CH—CH2—,
• (3) φ—CH═CH—CH2— which comprises:
• (1) contacting a hydroxy-amino compound of formula (V),
• where RN is as defined above, with strong base,
• (2) contacting the reaction mixture of step (1) with a compound of the formula RS—SO2—X where RS is phenyl or substitute phenyl and where X is —Cl and —Br and
• (3) contacting the reaction mixture of step (2) with a weak base.