Triethylamine → HCID 131724835, compound

Temperature

0 °C

3-[3,4,5-Tris-benzyloxy-6-(tert-butyl-dimethyl-silanyloxymethyl)-tetrahydro-pyran-2-yl]-propan-1-ol (from Example 8) (2.2 g, 3.6 mmol) and triethylamine (0.56 ml, 4 mmol) were dissolved in dry dichloromethane (10 ml) and cooled to 0° C. under an atmosphere of nitrogen. To this solution was added methanesulfonylchloride (0.29 ml, 3.8 mmol) and the resultant mixture stirred for 2 hours before diluting with ether (40 ml). The precipitate was removed by centrifugation and the supernatant evaporated under reduced pressure. The crude mesylate was dissolved in dimethylformamide (10 ml), sodium azide (1.17 g, 18 mmol) added and the mixture heated at 70° C. overnight. The mixture was cooled, diluted with ethyl acetate (100 ml) and washed with 1M hydrochloric acid (2×100 ml), saturated sodium bicarbonate (2×100 ml) and brine (100 ml), dried over anhydrous sodium sulfate, and evaporated to dryness. The residue was purified on a rapid vacuum silica gel (0.040-0.063 mm) column eluted with light petroleum (200 ml), 5% ethyl acetate in light petroleum (200 ml), 10% ethyl acetate in light petroleum (200 ml), 25% ethyl acetate in light petroleum (200 ml), 50% ethyl acetate in light petroleum (2×200 ml) and 100% ethyl acetate (200 ml) to give 3-[3,4,5-tris-benzyloxy-6-(tert-butyl-dimethyl-silanyloxymethyl)-tetrahydro-pyran-2-yl]-propylazide (tlc silica gel, Rf 0.80 in 25% EtOAc/Light petroleum) as an oil (2.05 g, 90%). This compound (3.4 g, 5.4 mmol) dissolved in dry ether (10 ml) was added to a suspension of lithium aluminium hydride (614 mg, 16.1 mmol) in ether (50 ml) at 0° C. under an atmosphere of nitrogen. The resulting solution was allowed to warm to room temperature and stirred for 2 hours. During this reaction the silyl protecting group was also removed. The reaction was quenched with 2M sodium hydroxide (5 ml), diluted with water (50 ml) and extracted with ether (4×50 ml). The combined ethereal extracts were washed with brine, dried over sodium sulfate and evaporated to give crude [6-(3-amino-propyl)-3,4,5-tris-benzyloxy-tetrahydro-pyran-2-yl]-methanol, ESMS (+ve) 606 (M+H). This crude compound was reacted with butyric acid (486 mg, 5.4 mmol) activated with BOP reagent (2.4 g, 5.4 mmol) and diisopropylethylamine (1.7 ml, 10 mmol) in tetrahydrofuran (20 ml). After 2 hours the solvent was removed under reduced pressure and ethyl acetate (100 ml) added to the oily residue which was subsequently washed with 1M hydrochloric acid (2×100 ml), saturated sodium bicarbonate (2×100 ml) and brine (100 ml), dried over anhydrous sodium sulfate, and evaporated to dryness. The residue was purified on a rapid vacuum silica gel (0.040-0.063 mm) column eluted with light petroleum (200 ml), 5% ethyl acetate in light petroleum (200 ml), 10% ethyl acetate in light petroleum (200 ml), 25% ethyl acetate in light petroleum (200 ml), 50% ethyl acetate in light petroleum (200 ml) and 100% ethyl acetate (3×100 ml) to give N-[3-(3,4,5-tris-benzyloxy-6-hydroxymethyl-tetrahydro-pyran-2-yl)-propyl]-butyramide (tlc silica gel, Rf 0.38 in 100% EtOAc, ESMS (+) 562 (M+H), 584 (M+Na)) as an oil (1.9 g, 62%). This compound (1.85 g, 3.3 mmol) was dissolved in dry dichloromethane (10 ml) and triethylamine (585 μl, 4.2 mmol) and the mixture cooled to 0° C. whereupon phosphorous oxychloride (585 μl, 3.9 mmol) was added dropwise with stirring under an atmosphere of nitrogen. The mixture was allowed to warm to room temperature and stirred for 2 hours. The solvent was evaporated and the residue diluted with ether and centrifuged to remove insoluble salts. The supernatant was then evaporated and redissolved in a 1:1 mixture of acetone and water (20 ml) and kept at 45-50° C. for 2 hours. The solvent was removed under reduced pressure to give phosphoric acid mono-[3,4,5-tris-benzyloxy-6-(3-butyrylamino-propyl)-tetrahydro-pyran-2-ylmethyl] ester, ESMS (+ve) 642 (M+H), (−ve) 640 (M−H). This compound was dissolved with 1% formic acid in methanol (100 ml), 10% palladium on carbon (100 mg) added and hydrogenated at 40 psi overnight. The mixture was filtered through celite and the filtrate evaporated to dryness to give phosphoric acid mono-[6-(3-butyrylamino-propyl)-3,4,5-trihydroxy-tetrahydro-pyran-2-ylmethyl] ester, ESMS (−ve) 370 (M−H). From this was prepared the mono sodium salt by dissolving this compound in a 1:1 solution of water and ethanol (2 ml) and dropwise addition of this solution to sodium acetate (270 mg, 3.3 mmol) dissolved in ethanol (50 ml). The resulting precipitate was isolated by centrifugation to give phosphoric acid mono-[6-(3-hexyloxy-propyl)-3,4,5-trihydroxy-tetrahydro-pyran-2-ylmethyl] ester, monosodium salt as a white solid (850 mg, 69%). 1Hnmr (500 MHz, D2O): δ 0.74 (t, J=7.5 Hz, 3H), 1.32-1.54 (m, 4H), 1.66 (m, 2H), 2.06 (t, J=7.5 Hz, 2H), 3.08 (t, J=5.8 Hz, 2H), 3.32-3.92 (m, 7H).

1. customThe precipitate was removed by centrifugation
2. customthe supernatant evaporated under reduced pressure
3. dissolutionThe crude mesylate was dissolved in dimethylformamide (10 ml)
4. temperaturethe mixture heated at 70° C. overnight
5. temperatureThe mixture was cooled
6. washwashed with 1M hydrochloric acid (2×100 ml), saturated sodium bicarbonate (2×100 ml) and brine (100 ml)
7. dry with materialdried over anhydrous sodium sulfate
8. customevaporated to dryness
9. customThe residue was purified on a rapid vacuum silica gel (0.040-0.063 mm) column
10. washeluted with light petroleum (200 ml), 5% ethyl acetate in light petroleum (200 ml), 10% ethyl acetate in light petroleum (200 ml)

ORD record

ord-e0aa3beba3984c9e985831aa53d6e9fd

Source dataset

uspto-grants-2005_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06878690B2