Reaction #1951025

Reaction equation

2,5,6-Trichloro-3-formyl-1-(β-D-ribofuranosyl)indole

acethydrazine

water

→

4.32

Yield 56.0%

2,5,6-Trichloro-3-[N-(acetylamino)iminomethylidene]-1-(β-D-ribofuranosyl)indole

Yield 56.0%

Solvents

MeOH

Conditions

Workup

1. 1
   TemperatureThe resulting solution was heated on a 45 C oil bath for 16 h
2. 2
   TemperatureThe resulting suspension was cooled to 4 C
3. 3
   Filtrationfiltered
4. 4
   Washthe solids rinsed with cold water (25 mL)
5. 5
   workup.DISSOLUTIONThe solids were dissolved in DMF (0.5 mL)
6. 6
   workup.ADDITIONFractions containing product
7. 7
   Otherevaporated
8. 8
   Otherto yield a white crystalline solid, which
9. 9
   Otherwas recrystallized from acetone/MeOH

Procedure

2,5,6-Trichloro-3-formyl-1-(β-D-ribofuranosyl)indole (4.3, 109 mg, 0.29 mmol) was dissolved in MeOH (5 mL) to which was added acethydrazine (85 mg, 1.1 mmol). The resulting solution was heated on a 45 C oil bath for 16 h, then cooled to room temperature and poured into 15 mL of water. The resulting suspension was cooled to 4 C, then filtered and the solids rinsed with cold water (25 mL). The solids were dissolved in DMF (0.5 mL) and subjected to column chromatography (40×350 mm) on C18-reverse phase silica gel with 75% MeOH/H2O. Fractions containing product were pooled and evaporated to yield a white crystalline solid, which was recrystallized from acetone/MeOH to yield 70 mg (56%) of 4.32 as a white microcrystalline solid which is an inseparable mixture of isomers in a ratio of 60:40: mp 270-271 C; Rf0.2 (10% MeOH/CHCl3); 1H-NMR (500 MHz, DMSO-d6): (major isomer) δ 11.25 (s, 1H, D2O exch.), 8.56 (s, 1H), 8.27 (s, 1H), 8.18 (s, 1H), 5.94 (d, 1H), 5.40-5.36 (m, 2H, D2O exch.), 5.25 (d, 1H, D2O exch.), 4.42 (q, 1H), 4.13 (s, 1H), 3.98 (s, 1H), 3.70 (s, 2H), 2.24 (s, 3H); (minor isomer) δ 11.41 (s, 1H, D2O exch.), 8.56 (s, 1H), 8.44 (s, 1H), 8.32 (s, 1H), 5.94 (d, 1H), 5.40-5.36 (m, 2H, D2O exch.), 5.25 (d, 1H, D2O exch.), 4.42 (q, 1H), 4.13 (s, 1H), 3.98 (s, 1H), 3.70 (s, 2H), 1.95 (s, 3H). 13C-NMR (125 MHz, DMSO-d6): (major isomer) δ 171.39, 135.98, 133.15, 129.73, 126.01, 124.96, 123.86, 121.69, 115.41, 108.31, 88.78, 86.09, 71.41, 69.66, 61.10, 20.36; (minor isomer) δ 165.24, 138.70, 133.12, 129.82, 126.06, 124.96, 123.99, 122.17, 115.33, 108.51, 88.78, 86.09, 71.41, 69.66, 61.10, 21.67. HRMS (ES) m/z calcd. for C16H16Cl3N3O5.Na 458.0053, found 458.0043. Anal calcd for C16H16Cl3N3O5: C, 44.01; H, 3.69; N, 9.62. Found: C, 43.76; H, 3.75; N, 9.67.

Source