S. Hendershot

Appropriate column configurations for the rapid analysis and semipreparative purification of the radiolabeled drug flutamide by high-performance liquid chromatography

Flutamide, marketed as Eulexin, is used for treatment of metastic prostatic carcinoma. Purity of a radiolabeled batch for metabolism studies was first determined by reversed-phase HPLC on a 5 microm, 150x4.6 mm analytical column. The separation was then scaled up to give a semipreparative column (5 microm, 250x10 mm) purification procedure. Fraction analysis was done on a short rapid analysis (5 microm, 50x3.0 mm) column. Analysis of the final product was performed on the analytical column. All columns were YMC-Pack ODS-AQ. The analytical work involved large mass injections in order to have the required amounts of radioactivity needed for accurate impurity profile determinations, and the preparative work involved masses much larger than the calculated scale-up values. Ultraviolet and radiochromatograms of the drug on the various column configurations are compared. A 95.7% recovery of product was obtained, with radiochemical purity increased from 95.0 to 99.8%.

Synthesis of 3H and 14C labelled SCH 48461

3 H-Sch 47949, racemic 3 H-Sch 48461, was prepared at a specific activity of 40 mCi/mmole by Pt catalysed exchange with tritiated water. 3 H-Sch 48461 was prepared at a specific activity of 64.6 Ci/mmole by a Pd/C catalysed reduction of an olefinic intermediate. 14 C-Sch 48461 was prepared in 8 steps from 14 C-potassium cyanide with an overall radiochemical yield of 18.5%.

Synthesis of 3H and 14C‐SCH 27899 by fermentation and evaluation of in vivo label stability

3H and 14 C-Sch 27899 have been prepared by fermentation using the Micromonospora carbonacea organism. In the case of 3 H-Sch 27899, the label was incorporated by a single addition of 100 mCi of 70Ci/mmole L-[3H-methyl]-methionine to two flasks. For 14 C-Sch 27899, 48 mCi of 55 mCi/mmole L-[14C-methyl]-methionine was added in five aliquots to five flasks over a five day period. Both batches were isolated by solvent extraction, oxidized and purified by column chromatography and hplc. An overall incorporation of 7.8% was found from L-[3H-methyl]-methionine and 18.7% from L-[14C-methyl]-methionine. The in vivo stability of label of 3 H and 14 C-Sch 27899 was determined, with 14 C-Sch 27899 found to be a better choice for use in in vivo metabolism studies.

SYNTHESIS OF (3) H, (2) H4 AND (14) C-MK 3814 (Preladenant).

MK 3814 is a potent and selective antagonist of the A2a receptor. A2a receptor antagonists have the potential for the treatment of Parkinson disease. Three distinct isotopically labelled forms of MK 3814 were synthesized. [3 H]MK 3814 was prepared for a preliminary absorption, distribution, metabolism, and excretion data (ADME) evaluation of the compound and [14 C]MK 3814 for more definitive ADME work, including an absorption, metabolism, and excretion study in man. In addition, [2 H4 ]MK 3814 was prepared as an internal standard for a liquid chromatography mass spectrometry bioanalytical method. This paper discusses the synthesis of 3 isotopically labelled forms of MK 3814.

Synthesis of3H,2H4, and14C-MK 3814 (preladenant)

MK 3814 is a potent and selective antagonist of the A2a receptor. A2a receptor antagonists have the potential for the treatment of Parkinson disease. Three distinct isotopically labelled forms of MK 3814 were synthesized. [3 H]MK 3814 was prepared for a preliminary absorption, distribution, metabolism, and excretion data (ADME) evaluation of the compound and [14 C]MK 3814 for more definitive ADME work, including an absorption, metabolism, and excretion study in man. In addition, [2 H4 ]MK 3814 was prepared as an internal standard for a liquid chromatography mass spectrometry bioanalytical method. This paper discusses the synthesis of 3 isotopically labelled forms of MK 3814.

Synthesis of (3) H, (2) H4 and (14) C-SCH 417690 (Vicriviroc).

Vicriviroc or SCH 417690 is a potent and selective antagonist of the CCR5 receptor. CCR5 receptor antagonists have the potential for the treatment of HIV infections. Four distinct isotopically labelled forms of SCH 417690 were synthesized. Low specific activity [(3) H]SCH 417690 was prepared for a preliminary absorption, distribution, metabolism and excretion evaluation of the compound and [(14) C]SCH 417690 for more definitive absorption, distribution, metabolism and excretion work, including an absorption, metabolism and excretion study in man. In addition, high specific activity [(3) H]SCH 417690 was prepared for CCR5 receptor binding work and [(2) H4 ]SCH 417690 was prepared as an internal standard for a liquid chromatography-mass spectrometry bioanalytical method. The paper discusses the synthesis of four isotopically labelled forms of SCH 417690.

Synthesis of3H,2H4and14C-SCH 417690 (Vicriviroc): 3H,2H4and14C-SCH 417690

Vicriviroc or SCH 417690 is a potent and selective antagonist of the CCR5 receptor. CCR5 receptor antagonists have the potential for the treatment of HIV infections. Four distinct isotopically labelled forms of SCH 417690 were synthesized. Low specific activity [(3) H]SCH 417690 was prepared for a preliminary absorption, distribution, metabolism and excretion evaluation of the compound and [(14) C]SCH 417690 for more definitive absorption, distribution, metabolism and excretion work, including an absorption, metabolism and excretion study in man. In addition, high specific activity [(3) H]SCH 417690 was prepared for CCR5 receptor binding work and [(2) H4 ]SCH 417690 was prepared as an internal standard for a liquid chromatography-mass spectrometry bioanalytical method. The paper discusses the synthesis of four isotopically labelled forms of SCH 417690.

Use of fluorine-containing stationary phases for the separation of an alkyl bromide from its hydrocarbon analog by high-performance liquid chromatography

Radiolabelled Sch 13835, an inhibitor of platelet derived growth factor, was prepared by catalytic hydrogenolysis of a benzyl bromide precursor with tritium gas. Regular and deactivated reversed-phase HPLC stationary phases gave poor peak shapes and little resolution of Sch 13835 and the benzyl bromide precursor. Fluorodecyl and fluoroether stationary phases in the analytical reversed-phase mode gave baseline separation using organic-aqueous (no buffers) mobile phases. Elution orders were reversed on either phase by a change in the organic component from methanol to acetonitrile. The product is unstable in aqueous (or other protic) solvents, forming a ring-opened acid. Conditions were developed to successfully purify the compound by reversed-phase HPLC with minimal decomposition. A second analytical HPLC assay was developed using normal-phase solvents on a fluoroether stationary phase.