Patent ID: 8461345

Claim:
A process for preparing a compound of Formula 1 comprising coupling a compound of Formula 2 with a compound of Formula 3 in the presence of a polar aprotic solvent; to produce a compound of Formula 4 treating the compound of Formula 4 with an aqueous solution of about 7M sulfuric acid; stirring the mixture at a temperature of about 95-105° C. to obtain the compound of Formula 5 treating the compound of Formula 5 with triphosgene and diisopropylethylamine in the presence of tetrahydrofuran; stirring the solution until the reaction is complete; and treating the solution with anhydrous ammonia to obtain the compound of Formula 1; wherein each R 1 , R 2 , R 4 and R 5 is independently selected from hydrogen, aliphatic, optionally substituted aryl, nitro, CN, OW, CO 2 R′, CO 2 N(R′) 2 , NR′CO 2 R′, NR′C(O)NR' 2 , OC(O)NR' 2 , F, Cl, Br, I, OTs, OMs, OSO 2 R′, OC(O)R; each R′ is independently selected from hydrogen, C 1-6 aliphatic, or a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with 1 to 3 substituents independently selected from halo, C 1-6 alkoxy, cyano, nitro, amino, hydroxy, and C 1-6 aliphatic; each R 3 is selected from hydrogen, C 1-6 aliphatic and aryl optionally substituted with C 1-6 aliphatic, aryl, nitro, CN, CO 2 R′, CO 2 N(R′) 2 , OR′, NCO 2 R′, NR′C(O)N(R′) 2 , or OC(O)N(R′) 2 ; each X is Cl; and each Z is independently selected from C 1-6 aliphatic, benzyl, Fmoc, or —SO 2 R′.