2-Fluoroadenosine

2-fluoroadenosine is a member of adenosines and an organofluorine compound.

Manufacture of 2-fluoro-ara-adenineMW =41 1 .35g/mol MF =CComparative Compound (VI) (3.6 mmole) and palladium chloride (1.4 g, 7.9 mmole) were used as in Example 1. The pressure was about 35 psig. The reaction was complete in about 1 hour and gave a 66% yield of product (VII).A portion of the crude intermediate (0.10 g) was suspended in absolute ethanol (50 mL) and cooled in an ice bath. Anhydrous ammonia was bubbled through the suspension until it became homogeneous. The solution was then stored at 4 C. for three days, then concentrated under vacuum. The residue was recrystallized from 50% aqueous ethanol. The precipitate was collected by filtration and dried under vacuum at 90 C. to obtain 26.9 mg (about 27% yield for two steps after correction for samples) of fludarabine, mp 256 C. (decomp.), which was identical to an authentic sample by TLC, 1 H NMR and IR. was synthesised analogously to J. Heterocyclic Chem. 16, 157 (1979). After hydrolysis of the reaction mixture by adding 30 ml 1 M triethylammonium bicarbonate solution and stirring for 1 hour, the pyridine was removed in a vacuum and the residue was partitioned between 200 ml t-butylmethyl ether (MTB) and 150 ml water, the organic phase was separated and evaporated in a rotary evaporator. The residue was purified chromatographically on RP-18 with methanol/0.02 M acetate buffer pH 4 8/2 as the eluant. The fractions containing product were concentrated down to the water portion, extracted with MTB and the MTB phase was adjusted with sodium methylate solution against Friscolyt to pH 7. After the solvent was removed by evaporation the residue was suspended in acetone, the amorphous precipitate was suction filtered and dried. Yield: 23.7 g (43%). Amorph. Rf=0.45 (TLC-mobile solvent: isopropanol/butyl acetate/water/ammonia 50/30/15/5).EXAMPLE 4 Synthesis of 9-beta-D-Arabinofuranosyl-2-fluoroadenine 6-Azido-2-fluoro-9-(2, 3, 5-tri-O-benzyl-beta-D-arabinofuranosyl)purine (0.19 g) was dissolved in 2-methoxyethanol (20 mL) with palladium (II) chloride (PdCl2) (20 mg) and activated carbon and the mixture was hydrogenated at 55 pounds per square inch (psi) in a Parr shaker. The reaction was monitored by thin layer chromatography (TLC) until complete. The mixture was then filtered through celite and the filtrate was concentrated in vacuo. Three times, the residue was dissolved in ethanol and reconcentrated. Then the residue was recrystallized from ethanol/water to obtain 0.063 g of the title compound which was consistent in its structure with an authentic sample by IR and TLC.[Complete Deacylation] See Reaction Scheme 1; compound 9, wherein R1 and R3 are acetyl, to compound 10. A suspension of 2-fluoro-9-beta-D-(2', 3', 5'-tri-O-acetylarabinofuranosyl)adenine (1.27 g, 3.08 mol) in absolute ethanol (130 mL) was magnetically stirred and cooled to 0 C. in an ice-brine bath under nitrogen. Anhydrous ammonia was bubbled through the suspension until it became homogeneous (30 minutes). The flask was then sealed with a septum and placed in a refrigerator at 0-4 C. After four days, the mixture was concentrated under vacuum. The residue was triturated with chloroform to yield 0.88 g of powder which consisted of a 3:1 molar ratio complex of the title compound and acetamide. This was recrystallized from 25 mL of 50% aqueous ethanol. The resulting solid was collected by filtration, washed with aqueous ethanol, air-dried overnight and then dried at 100 C. under vacuum over P2 O5 to obtain 0.75 g (85%) of pure fludarabine in its anhydrous form. mp 252-254 C.; 1 H NMR (DMSO-d6) delta 3.6-3.75 (m, 2H, 2H-5') 3.77 (q, 1H, H-4'), 4.05-4.2 (m, 2H, H-2', and H-3'), 5.07 (t, 1H, 5'-OH), 5.52 (d, 1H, OH), 5.63 (d, 1H, OH), 6.11 (d, 1H, H-1'), 7.8 (bs, 2H, NH2), 8.17 (s, 1H, H-8); FT-IR (KBr) 3455, 3308, 3185, 1641, 1378 cm-1.9-beta-D-Arabinofuranosyl-2-fluoroadenine (VII) Concentrated hydrochloric acid (0.5 mL/g of nucleoside, 50 mL, 0.608 mol) was added to a suspension of intermediate VI (100 g, 0.180 mol) in methoxyethanol (500 mL) to give a homogeneous yellow solution to which palladium chloride (3.0 g) and Norit A (10 g) were added. The mixture was flushed with hydrogen (2 * 20 psig) and the hydrogen pressure was raised to 50 psig. After 10 minutes the pressure which had fallen to 2 psig was adjusted back to 50 psig. The process was repeated twice more until there was no further hydrogen uptake (total time, 50 minutes). No starting material was present by tlc. The catalyst was removed through a celite bed and the filter cake was washed with methoxyethanol (2 * 50 mL). The filtrate was cooled (ice-bath) and concentrated ammonium hydroxide (~ 55 mL) was added to pH ~ 8 (light-pink color). The precipitate (NH4 Cl) was removed by filtration and the filtrate was concentrated to near dryness. The resulting solid was slurried with water (150 mL), filtered and washed with ethanol (50 mL) to give 55 g of crude product (air-dried). The crude product was recrystallized from hot ethanol-water (1.6 L, 1:1 v/v) to afford, after air-drying, 44 g (81% as a monohydrate) of the title nucleoside VII, mp 264-266 C. (dec). In this manner a total of 3.15 kg of protected nucleoside was processed to give 1.53 kg of crude air-dried product. The crude product was recrystallized from hot ethanol-water (30 mL/g, 46 L, 1:1 v/v) and dried at 90 C., 0.3 mmHg for 24 hours to give pure anhydrous title compound (VII), 1.295 kg (80%, average yield), mp 264-266 C. (dec); lambda max (H2 O) 261 nm (epsilon= 15, 100). Anal. Calcd for C10 H12 FN5 O4 (285.24): C, 42.11; H, 4.24; F, 6.66; N, 24.55. Found: C, 42.00; H, 4.40; F, 6.60; N, 24.61.Preparation of Prodrug Forms of 9-beta-D-arabinofuranosyl-2-fluoroadenine STR1 The 5'-formyl derivative (R=CHO) of F-ara-A was prepared by the reaction for F-ara-A with cold 98% formic acid. It was isolated by acetone extraction followed by reverse-phase high-pressure liquid chromatography on a C18 using water-acetonitrile as eluant. The 5'-phosphate (R=H2 PO3 --) of F-ara-A was prepared by the reaction of F-ara-A with phosphorous oxychloride in an alkyl phosphate followed by hydrolysis in water.B. 9-beta-D-Arabinofuranosyl-2-fluoroadenine (I) BCl3 gas (72.9) was bubbled in CH2 Cl2 (610 ml) at 0in a 2-l., 3-necked flask equipped with a thermometer, magnetic stirrer, and addition funnel and the stirred solution then cooled to -72 (dry ice-acetone) before the dropwise addition (1 hr) of a cold solution of 9-(2, 3, 5-tri-O-benzyl-beta-D-arabinofuranosyl)-2-fluoroadenine (II, 7.0 g, 12.5 mmol) in CH2 Cl2 (70 ml). After a total reaction time of 23/4 hr, the cooling bath was removed and the solvent and gas removed in vacuo. The residue was dissolved in CH2 Cl2 (40 ml) and the solution evaporated to dryness (six times), or until a solid white residue is obtained, before adding 450 ml of 5% NaHCO3 followed by solid NaHCO3 to adjust the pH to 6-7. The mixture was diluted with EtOH, heated to boiling, treated with charcoal, filtered through Celite, and then allowed to stand at room temperature overnight. It was then chilled and the solid collected by filtration, washed with cold H2 O and then ether, and dried in vacuo; yield 3.23 g (91%); mp 259-260; homogeneous according to TLC (19:1) and HPLC (23 H2 O:2 MeCN); pmr; 3.7 (m, H4'; and 2H5';), 4.15 (m, H2'; and H3';), 5.1 (t, 5'-OH), 5.55 and 5.65 (2d, 2'-OH and 3'-OH), 6.14 (d, J1'2' 3Hz, H1'), 7.8 (broad s, NH2), 8.2 (s, H8); uv: pH 1--262 (13.2); ph 7, 13--261 (15.3).9-beta-D-Arabinofuranosyl-2-fluoroadenine (7). Boron trichloride gas was bubbled in methylene chloride (610 ml.) at 0 in a 2-l., 3-necked flask equipped with a thermometer, magnetic stirrer, and addition funnel and the stirred solution then cooled to -72 (dry ice-acetone) before the dropwise addition (1 hour) of a cold solution of 9-(2, 3, 5-tri-O-benzyl-beta-D-arabinofuranosyl)-2-fluoroadenine (6, 7.0 g., 12.5 mmoles) in methylene chloride (70 ml.). After a total reaction time of 2.75 hours, the cooling bath was removed and the solvent and gas removed in vacuo. The residue was dissolved in cold methylene chloride (40 ml.) and the solution evaporated to dryness (6 times) or until a solid white residue was obtained, before adding 450 ml. of cold 5% sodium bicarbonate followed by solid sodium bicarbonate to adjust the pH to 6-7. The mixture was diluted with ethanol, heated to boiling, treated with charcoal, filtered through Celite, and then allowed to stand at room temperature overnight. It was then chilled and the solid collected by filtration, washed with cold water and then ether, and dried in vacuo; yield 3.23 g. (91%); m.p. 259-260; homogeneous according to tlc (19:1) and hplc (23 water:2 acetonitrile); nmr: 3.7 (m, H4' and 2H5'), 4.15 (m, H2' and H3'), 5.1 (t, 5'--OH), 5.55 and 5.65 (2d, 2'-13 OH and 3'--OH), 6.14 (d, J'2' 3 Hz, H1'), 7.8 (broad s, NH2), 8.2 (s, H8); uv: pH 1-262 (13.2); pH 7, 13-261 (15.3).Pure 9-beta-D-arabinofuranosyl-2-fluoroadenine (II) 9-beta-D-arabinofuranosyl-2-fluoroadenine (II) (30 g, 0, 095 moles) was suspended in acetic anhydride (300 ml) and heated to 95C under stirring. After 7 hours a clear solution was obtained and left to react at 95C for further 2-3 hours until the acetylation was completed. The resulting yellow solution was then concentrated under vacuum at 45C and the residue was co-evaporated with acetone (2 x 50 ml) and suspended in water (600 ml). The water suspension was cooled to room temperature and left under stirring for 1 hour. The product was collected by filtration and washed with water (2 x 100 ml) to give 34 g of wet 2', 3', 5'-tri-O-acetyl-9-beta-D-arabinofuranosyl-2-fluoroadenine(III). Wet compound (III) was suspended in methanol (300 ml) and added with 25% NH4OH (100 ml). The mixture was left to stand at room temperature overnight and after 19 hours was warmed to 30-32C for 3 hours, until no starting material was detected by HPLC. The suspension was cooled to 10C for 1 hour, then the product was collected by filtration and washed with a methanol-water mixture (2 x 25 ml, 3:1 v/v). The product was dried under vacuum at 45C overnight to give 17.5 g of fludarabine (II) (98.4% HPLC purity).Chemotherapeutic agents that are bound to monoclonal antibodies of the present invention to drive the cytotoxic activity include the following: ... estramustine, etoposide, etoposide glucuronide, floxuridine, fludarabine, flutamide, fluorouracil, fluoxymesterone, ...Illustrative examples of chemotherapeutic agents which may be conjugated with the antibody of the invention and have a cytotoxic effect include: ... estramustine, etoposide, etoposide glucuronide, floxuridine, fludarabine, flutamide, fluorouracil, fluoxymesterone, ...Compound 7 (300 mg, 0.61 mmol) was put into a 25 mL pressure-resistant tube, 10 mL of ammonia-saturated methanol solution was quickly added, and the bottle mouth was sealed.After the reaction solution was reacted at 40 C for 6 hours, the solvent was removed by rotary evaporation under reduced pressure.The concentrate was separated and purified by flash silica gel column chromatography, and the elution solvent was dichloromethane / methanol (20: 1 to 10: 1, V: V).0.156 g of fludarabine was obtained in a yield of 90%.

Used as intermediate of drug fludarabine

Molecular Weight:285.23
XLogP3:-0.6
Hydrogen Bond Donor Count:4
Hydrogen Bond Acceptor Count:9
Rotatable Bond Count:2
Exact Mass:285.08733204
Monoisotopic Mass:285.08733204
Topological Polar Surface Area:140
Heavy Atom Count:20
Complexity:367
Defined Atom Stereocenter Count:4
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes