4-Amino-3,5-dichloropyridine → Piclamilast

HRID 356887Notes

Reaction equation

HRID 356887 reaction equation
[NH2:1][C:2]1[C:7]([Cl:8])=[CH:6][N:5]=[CH:4][C:3]=1[Cl:9].[CH:10]1([O:15][C:16]2[CH:17]=[C:18]([CH:22]=[CH:23][C:24]=2[O:25][CH3:26])[C:19](Cl)=[O:20])[CH2:14][CH2:13][CH2:12][CH2:11]1>>[Cl:9][C:3]1[CH:4]=[N:5][CH:6]=[C:7]([Cl:8])[C:2]=1[NH:1][C:19](=[O:20])[C:18]1[CH:22]=[CH:23][C:24]([O:25][CH3:26])=[C:16]([O:15][CH:10]2[CH2:11][CH2:12][CH2:13][CH2:14]2)[CH:17]=1

Participants

3

Reactant 2

HCID 898884-Amino-3,5-dichloropyridineHCID 27946003-(Cyclopentyloxy)-4-methoxybenzoyl chloride

Product 1

HCID 154575PiclamilastYield 20%

Procedure

4-Amino-3,5-dichloropyridine (4.0 g) and 3-cyclopentyloxy-4-methoxybenzoyl chloride (6.26 g) are intimately ground together in a mortar with a pestle, and transferred to a round-bottomed flask. The mixture is melted, using a hot air gun external to the flask, stirring with a magnetic stirrer. After 10 minutes, heating is ceased and the melt is allowed to cool. The resulting material is triturated with dichloromethane and the residual solid is filtered off. The filtrate is concentrated to give a fawn solid, which is subjected to flash chromatography on silica gel, eluting with diethyl ether, to give N-(3,5-dichloro-pyrid-4-yl)-3-cyclopentyloxy-4-methoxybenzamide (1.87 g), m.p. 155°-157° C. [Elemental analysis: C,56.3; H,4.7; N,7.2; CI,18.4%; calculated: C,56.7; H,4.76; N,7.35; Cl18.6%; IR spectrum: 1661 cm-1, 3244 cm-1 ]

Workup

  1. customtransferred to a round-bottomed flask
  2. temperatureheating
  3. temperatureto cool
  4. customThe resulting material is triturated with dichloromethane
  5. filtrationthe residual solid is filtered off
  6. concentrationThe filtrate is concentrated
  7. customto give a fawn solid, which
  8. washeluting with diethyl ether

Sources & evidence

ORD record
ord-235625888b594aee981a6be31ed4a2dc
Source dataset
uspto-grants-1998_11
Patent number
US05840724

Reaction notes

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