We report the formal synthesis of angiogenesis inhibitor NM-3 (1) in six steps from either of the 2,4-dimethoxyhalobenzenes 13a,b or 3,5-dimethoxychlorobenzene (13c). The first key reaction is the regiospecific alkylation/rearrangement between the aryne derived from 13a-c with sodium diethylmalonate in THF to produce diester 11, which after hydrolysis and cyclization affords homophthalic anhydride 3. The second is the reaction of anhydride 3 with either ethyl 2-methylmalonate (28a), in the presence of 1,1'-carbonyldiimidazole, or ethyl-2-methylmalonyl chloride (28b) under basic conditions to afford key isocoumarin 27. The conversion of 27 constitutes a formal synthesis of NM-3.

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Clofarabine is a promising DNA polymerase inhibitor currently in clinical trials for a variety of liquid and solid tumor indications. The efforts for development of a new manufacturing process for clofarabine are presented. This new process allows for the reliable and efficient production of drug substance in high anomeric excess and high overall purity, without using chromatography. The high anomeric selectivity is achieved by reacting 2-chloroadenine with 1-bromo-2-deoxy-2-fluoro-3,5-di-O-benzoyl-α-d-ribofuranose (4) and potassium ter t-butoxide in a mixture of three solvents. Following crystallization, anomeric ratios exceeding 50 (β/α) are achieved. Deprotection and additional crystallization afford a clofarabine drug substance containing less than 0.1% of the α-anomer.

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The identification of clofarabine process impurities and their subsequent isolation, synthesis, and characterization is described. Two isomeric process impurities resulting from N 6 -attachment of a fluoroarabinose to clofarabine were found. Clofarabine's base degradation products, which were different from the process impurities, were also synthesized and characterized. These compounds resulted from modifications to the sugar moiety, the purine ring, or both. A mechanistic rationale for the formation of the