Sodium borohydride → 1H-Pyrazole-3-carboxylic acid, 1-(1,1-dimethylethyl)-4-(hydroxymethyl)-, ethyl ester

HRID 880907Notes

Reaction equation

HRID 880907 reaction equation
[C:1]([N:5]1[CH:9]=[C:8]([CH:10]=[O:11])[C:7]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[N:6]1)([CH3:4])([CH3:3])[CH3:2].[BH4-].[Na+]>C(O)C>[C:1]([N:5]1[CH:9]=[C:8]([CH2:10][OH:11])[C:7]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[N:6]1)([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 71743490HCID 71743490, compound

Product 1

HCID 674914531H-Pyrazole-3-carboxylic acid, 1-(1,1-dimethylethyl)-4-(hydroxymethyl)-, ethyl esterYield 88.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of ethyl 1-tert-butyl-4-formyl-1H-pyrazole-3-carboxylate (2.87 g, 12.8 mmol) in ethanol (50 mL) was added sodium borohydride (0.97 g, 25.6 mmol) in one portion. After stirring for 30 minutes at room temperature the mixture was quenched with 1 N aqueous hydrochloric acid (100 mL), stirred for 15 minutes, and then neutralized with saturated aqueous sodium bicarbonate. The mixture was extracted with ethyl acetate (2×150 mL), the combined organics then dried over sodium sulfate, filtered and concentrated to yield ethyl 1-tert-butyl-4-(hydroxymethyl)-1H-pyrazole-3-carboxylate (2.57 g) as a clear oil. +APCI (M+Na) 249.2; 1H NMR (400 MHz, CDCl3, δ): 7.49 (s, 1H), 4.65 (d, J=6.8 Hz, 2H), 4.43 (q, J=7.2 Hz, 2H), 3.62 (t, J=6.9 Hz, 1H), 1.59 (s, 9H), 1.41 (t, J=7.1 Hz, 3H).

Workup

  1. customwas quenched with 1 N aqueous hydrochloric acid (100 mL)
  2. stirringstirred for 15 minutes
  3. extractionThe mixture was extracted with ethyl acetate (2×150 mL)
  4. dry with materialthe combined organics then dried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-d23e7595faad44168c651506817a7219
Source dataset
uspto-grants-2015_03
Patent number
US08993586B2

Reaction notes

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