To a solution of acid 120 (0.25 g, 1.11 mmol) in CHCl3 (20 mL) and CH3CN (20 mL) at 0° C. was added oxalyl chloride (0.84 g, 6.69 mmol) and a catalytic amount of DMF. The resulting solution was stirred for 2 h at rt and concentrated in vacuo. The residue was re-dissolved in CHCl3 and the resulting solution cooled to 0° C. To this mixture was added N-methyl-4-isopropyl aniline (0.29 g, 2 mmol) and the reaction was stirred overnight warming to rt. The reaction was then diluted with CHCl3 (30 mL) and washed with 1 N HCl (50 mL). The combined organic layers were washed with water (75 mL), dried over Na2SO4 and concentrated in vacuo and the product was purified by chromatography on silica gel eluting with EtOAc/hexanes and EtOAc/MeOH to yield 392 (0.2 g, 51%) as a light brown solid. mp: 271-273° C. MS (APCI): m/z 356.2 [M+H]+ Anal. Calcd. For C18H21N5O3.0.35H2O: C, 59.77; H, 6.05; N, 19.36. Found C, 59.77; H, 6.07; N, 19.29.
