Trityl chloride → 1-methyl-4-(trityl-amino)-1H-pyrazole-3-carboxylic acid methyl ester

HRID 720686Notes

Reaction equation

HRID 720686 reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:9]([NH2:10])=[CH:8][N:7]([CH3:11])[N:6]=1)=[O:4].C(N(CC)CC)C.[C:19]1([C:25](Cl)([C:32]2[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=2)[C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1>CN(C)C=O>[CH3:1][O:2][C:3]([C:5]1[C:9]([NH:10][C:25]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)([C:32]2[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=2)[C:26]2[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=2)=[CH:8][N:7]([CH3:11])[N:6]=1)=[O:4]

Participants

5

Reactant 3

HCID 6456Trityl chlorideHCID 8471TriethylamineHCID 7017722methyl 4-amino-1-methyl-1H-pyrazole-3-carboxylate

Product 1

HCID 587392481-methyl-4-(trityl-amino)-1H-pyrazole-3-carboxylic acid methyl esterYield 91.1%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A solution of 4-amino-1-methyl-1H-pyrazole-3-carboxylic acid methyl ester (160 mg, 1.03 mmol) in N,N-dimethylformamide (1.0 mL) at 25° C. was treated with triethylamine (0.35 mL, 2.6 mmol) and triphenylmethylchloride (316 mg, 1.13 mmol). Additional N,N-dimethylformamide (2.0 mL) was added to the reaction to aid stirring. The reaction was stirred at 25° C. for 18 h. At this time, the reaction was concentrated in vacuo. The residue was dissolved in dichloromethane (50 mL) and then was washed with a IN aqueous hydrochloric acid solution (1×10 mL), a saturated aqueous sodium bicarbonate solution (1×10 mL), and a saturated aqueous sodium chloride solution (1×10 mL). The organics were dried over magnesium sulfate, filtered, and concentrated in vacuo to afford 1-methyl-4-(trityl-amino)-1H-pyrazole-3-carboxylic acid methyl ester (373 mg, 91.1%) as an off-white solid: 1H NMR (DMSO-d6, 300 MHz) δ7.25 (m, 16H), 3.74 (s, 3H), 3.53 (s, 3H).

Workup

  1. stirringThe reaction was stirred at 25° C. for 18 h
  2. concentrationAt this time, the reaction was concentrated in vacuo
  3. dissolutionThe residue was dissolved in dichloromethane (50 mL)
  4. washwas washed with a IN aqueous hydrochloric acid solution (1×10 mL)
  5. dry with materialThe organics were dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-2a99f9ec0d504618b1f6b98c55dbfc2b
Source dataset
uspto-grants-2006_11
Patent number
US07135475B2

Reaction notes

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