Tetrahydrofuran → Methyl 2,4,5-triamino-3-fluorobenzoate

HRID 1888962Notes

Reaction equation

HRID 1888962 reaction equation
[NH2:1][C:2]1[C:11]([F:12])=[C:10]([NH2:13])[C:9]([N+:14]([O-])=O)=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].O1CCCC1>CO.[Pd]>[NH2:1][C:2]1[C:11]([F:12])=[C:10]([NH2:13])[C:9]([NH2:14])=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5]

Participants

5

Procedure

A mixture of methyl 2,4-diamino-3-fluoro-5-nitrobenzoate (5) (40.0 g, 173.7 mmol) and 5% Pd/C (3.0 g, Type 487; 0.4 mol % Pd relative to starting material), in methanol (300.0 mL) and tetrahydrofuran (300.0 mL) was stirred at 2000 RPM, under hydrogen (˜3.5 bar), at 50° C. in a 1.5 L hydrogenation vessel. After 6 hours the vessel was purged with nitrogen and HPLC analysis indicated that no starting material remained. The mixture was then filtered under nitrogen pressure and the filter washed through with THF (160 mL), to give a clear yellow solution. The solvent was removed by rotary evaporation, to provide methyl 2,4,5-triamino-3-fluorobenzoate (9) 37.5 g (93.3% w/w by NMR) as a solid, yield ˜100%. 1H NMR (400 MHz, d6 DMSO) δ 3.69 (3H, s, NMe), 4.20 (2H, br s, NH2), 5.24 (2H, br s, NH2), 5.70 (2H, br s, NH2), 6.83 (1H, d, J 1, Ar—H). 13C NMR (100 MHz, d6 DMSO) δ 51 (CH3), 98 (C, d, J 5), 110 (CH, d, J 2), 125 (C, d, J 6), 131 (C, d, J 12), 133 (C, d, J 12), 139 (CF, d, J 225), 166 (C═O). νmax/cm-1 3480, 3461, 3373, 3356, 3280, 3163, 1679, 1655, 1314. MS APCI (+) m/z 200 (M+1) detected.

Workup

  1. customAfter 6 hours the vessel was purged with nitrogen and HPLC analysis
  2. filtrationThe mixture was then filtered under nitrogen pressure
  3. washthe filter washed through with THF (160 mL)
  4. customto give a clear yellow solution
  5. customThe solvent was removed by rotary evaporation

Sources & evidence

ORD record
ord-eccdfe5c2c9e4df5a6f5c8066048dc28
Source dataset
uspto-grants-2013_08
Patent number
US08501956B2

Reaction notes

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