Development of an efficient and scalable process for the human immunodeficiency virus (HIV) protease inhibitor BMS-232632 1-[4-(pyridin-2-yl)phenyl]-5(S)-2,5-bis{[N-(methoxycarbonyl)-L-tert-leucinyl]-amino}-4(S)-hydroxy-6-phenyl-2-azahexane, is described. The key step in the synthesis of the intermediate N-1-(tert-butyloxycarbonyl)-N-2-[4-(pyridin-2-yl)benzylidene]hydrazone (11) was the Pd-mediated coupling of boronic acid 9 with 2-bromopyridine. An efficient procedure was developed for the chemoselective reduction of hydrazone 11 to hydrazine carbamate 4 (6) was prepared stereoselectively from chiral diol 10. The subsequent union of 4 and 6 followed by coupling with N-methoxycarbonyl-L-tert-leucine provided the free base BMS-232632 in high yield. Evaluation of a variety of salts and identification of bisulfate salt 19 with enhanced bioavailability are also described. . The key intermediate N-(tert-butyloxycarbonyl)-2(S)-amino-1-phenyl-3(R)-3,4-epoxy-butane

A study of the process-property-performance relationship of a Bristol-Myers Squibb drug substance led to successful development of crystallization and drying processes that produce crystals with desired and consistent physical properties. A controlled crystallization technique was developed to obtain well-defined, large crystals with a narrow particle size distribution. This crystallization process provided a less compressible filter cake for effective cake washing and deliquoring and afforded an easily dried product with desired powder properties. To preserve the quality of the crystals during drying, a drying protocol using low shear agitation was developed. This protocol prevented crystal attrition during drying, which was shown to adversely affect the formulation process and, thus, drug product performance. API crystals prepared by this method consistently resulted in excellent formulation processing and drug product performance.

A practical synthesis of the SGLT-2 inhibitor β-C-aryl-D-glucoside (1) has been developed. The route employed 2,3,4,6-tetra-O-trimethlysilyl-D-glucano-1,5-lactone as the key chiral building block, prepared efficiently from the commercially available, inexpensive raw materials, D-gluconolactone and trimethylsilyl chloride. The salient step in the synthesis is the Lewis acid-mediated stereoselective reduction of a methyl C-aryl peracetylated glycoside using a silyl hydride to set the stereochemistry of the crucial anomeric chiral center. Several novel cocrystalline complexes of 1 with L-phenylalanine and L-proline were discovered. Single-crystal structures of these complexes and several synthetic intermediates have been determined. The Lphenylalanine complex was developed and used to purify and isolate the API. All steps were implemented at multikilogram scale.

The diffusion process is dependent upon temperature. The key to a successful scale up of the secondary drying is to control the drying temperature. The fate of primary solvents including methanol and acetone, and their potential impurity such as benzene can be described by the Fickian diffusion model. A mathematical relationship based upon the ratio of diffusion coefficient was established to predict the benzene concentration from the fate of the primary solvent during the secondary drying process.

The objective of this study is to recover Active Pharmaceutical Ingredients (APIs) from tablets via green engineering technology to meet material requirements for downstream formulation development. A separation train, using water as the separation media, includes dissolution, centrifugal phase separation, diafiltration and reverse osmosis and has been developed based on the physical properties of the API and excipients. These properties include solubility, multiphase behaviors, particle densities, and size differences between API and excipients. The recovered API both meets purity specifications and contains no polymer. It is suitable for reuse in formulation process development. The recovery of the API from tablets is over 90%. A green engineering technology using water and separation methods is successfully developed and used to recover API from tablets.