p-Toluenesulfonic acid → Methyl 4-nitro-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-3-carboxylate

HRID 2064683Notes

Reaction equation

HRID 2064683 reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][NH:7][N:6]=1)=[O:4].C1(C)C=CC(S(O)(=O)=O)=CC=1.[O:24]1[CH:29]=[CH:28][CH2:27][CH2:26][CH2:25]1>C(Cl)(Cl)Cl>[CH3:1][O:2][C:3]([C:5]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][N:7]([CH:25]2[CH2:26][CH2:27][CH2:28][CH2:29][O:24]2)[N:6]=1)=[O:4]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 178499180HCID 178499180, compound

Product 1

HCID 20784940Methyl 4-nitro-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

A suspension of 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester (1.3 g, Reference Example 55) and p-toluene sulfonic acid (144 mg) in chloroform (30 ml) at 0° C. was treated with 3,4-dihydropyran (1.04 ml) dropwise. The reaction mixture was allowed to warm to room temperature overnight. The reaction mixture was washed with saturated sodium bicarbonate (40 ml) and water (3×40 ml). The combined aqueous layers were extracted with dichloromethane (3×60 ml). The organic layers were combined, dried over magnesium sulfate and concentrated to yield 4-nitro-1-(tetrahydro-pyran-2-yl)-1H-pyrazole-3-carboxylic acid methyl ester (2.23 g) as a viscous brown oil. LC-MS (Method H): RT=2.79 minutes, 278.21 (M+H+ Na)+.

Workup

  1. washThe reaction mixture was washed with saturated sodium bicarbonate (40 ml) and water (3×40 ml)
  2. extractionThe combined aqueous layers were extracted with dichloromethane (3×60 ml)
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-4d69111822bb44c98b78c2f795b77fd6
Source dataset
uspto-grants-2012_10
Patent number
US08288425B2

Reaction notes

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