Dimethyl Sulfoxide → Methyl 4-amino-3,5-dichloro-6-phenoxypyridine-2-carboxylate

HRID 378802

Reaction equation

HRID 378802 reaction equation
[NH2:1][C:2]1[C:7]([Cl:8])=[C:6](Cl)[N:5]=[C:4]([C:10]([OH:12])=[O:11])[C:3]=1[Cl:13].[C:14]1([OH:20])[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.[OH-].[Na+].[CH3:23]S(C)=O>O>[NH2:1][C:2]1[C:7]([Cl:8])=[C:6]([O:20][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[N:5]=[C:4]([C:10]([O:12][CH3:23])=[O:11])[C:3]=1[Cl:13]

Participants

6

Reactant 4

HCID 679Dimethyl SulfoxideHCID 996PhenolHCID 14798Sodium HydroxideHCID 15965Picloram

Product 1

HCID 21696627Methyl 4-amino-3,5-dichloro-6-phenoxypyridine-2-carboxylateYield 14%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A solution of 4-amino-3,5,6-trichloropyridine-2-carboxylic acid (7.2 g, 0.03 mol), phenol (3.0 g, 0.036 mol) and sodium hydroxide (2.7 g 0.068 mol) in DMSO (60 mL) and water (9 mL) was heated to 130° C. for 18 hr. The reaction was diluted with water (250 mL) and a tacky solid collected. This material was dissolved in methanol (100 mL) and treated with TMSCHN2 (25 mL 2M in hexanes). The reaction was stirred 30 min and concentrated. The resulting oil was chromatographed over silica gel (80% hexane and 20% ethyl acetate) to give methyl 4-amino-3,5-dichloro-6-phenoxypyridine-2-carboxylate (1.2, g, 14%); mp 88-90° C.

Workup

  1. customa tacky solid collected
  2. dissolutionThis material was dissolved in methanol (100 mL)
  3. additiontreated with TMSCHN2 (25 mL 2M in hexanes)
  4. concentrationconcentrated
  5. customThe resulting oil was chromatographed over silica gel (80% hexane and 20% ethyl acetate)

Sources & evidence

ORD record
ord-3bf316338c504e9f9a449d19bfd56465
Source dataset
uspto-grants-2001_10
Patent number
US06297197B1

Linked notes

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