3,4-dihydro-2H-pyran → 4-Bromo-5-methyl-1-(tetrahydro-pyran-2-yl)-3-trifluoromethyl-1H-pyrazole

HRID 75212Notes

Reaction equation

HRID 75212 reaction equation
[Br:1][C:2]1[C:3]([C:8]([F:11])([F:10])[F:9])=[N:4][NH:5][C:6]=1[CH3:7].O.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>[Br:1][C:2]1[C:3]([C:8]([F:9])([F:11])[F:10])=[N:4][N:5]([CH:25]2[CH2:26][CH2:27][CH2:28][CH2:29][O:24]2)[C:6]=1[CH3:7]

Participants

5

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 521998p-Toluenesulfonic acid monohydrateHCID 27364304-Bromo-3-methyl-5-(trifluoromethyl)pyrazole

Product 1

HCID 593319834-Bromo-5-methyl-1-(tetrahydro-pyran-2-yl)-3-trifluoromethyl-1H-pyrazoleYield 86.2%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 4-bromo-5-methyl-3-(trifluoromethyl)-1H-pyrazole (1.00 g, 4.37 mmol) and p-toluenesulfonic acid monohydrate (80 mg, 0.4 mmol) in CHCl3 (3.5 mL) was cooled to 0° C. and dihydropyran (480 μL, 5.2 mmol) was added dropwise. The reaction was stirred at 0° C. for 1.5 h. The solvent was removed in vacuo and the residue was purified by column chromatography to obtain the desired product (1.18 g, 86%). 1H NMR (400 MHz, CDCl3): δ 5.35 (dd, 1H), 3.98 (m, 1H), 3.65 (m, 1H), 2.40 (m, 1H), 2.37 (s, 3H), 2.12 (m, 1H), 1.96 (m, 1H), 1.64 (m, 3H).

Workup

  1. customThe solvent was removed in vacuo
  2. customthe residue was purified by column chromatography

Sources & evidence

ORD record
ord-aaa184edde1441c380706128d71470c2
Source dataset
uspto-grants-2014_09
Patent number
US08835423B2

Reaction notes

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