Patent ID: 7323562

Claim:
A method of preparing a compound of formula I wherein R 1 is: H; cyano; an optionally unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl group; or —C(O)—R 5 , where R 5 is: H; an optionally unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl group; or OR 6 or NR 6 R 7 , where R 6 and R 7 are each independently H or an optionally unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl group; R 2 is H; R 3 is H or alkyl; R 4 is H, halogen or alkyl, the method comprising: a) Sonogashira coupling of a compound of formula II, wherein X is halogen or CF 3 SO 2 —O— with a compound of formula III to form a compound of formula IV b) reducing the compound of formula IV to generate a compound of formula V; c) converting the compound of formula V into a compound of formula VI; d) treating the compound of formula VI with N,N-dimethyl-2-nitroethylenamine to form a compound of formula VII e) reducing the compound of formula VII to form a compound of formula VIII f) converting the compound of formula VIII by reduction with Raney-Ni and subsequent cyclization with base into the compound of formula I.