tert-Butanol → 5-(Boc-amino)-3-chloro-1-methyl-1H-pyrazole

HRID 402487

Reaction equation

HRID 402487 reaction equation
[Cl:1][C:2]1[CH:6]=[C:5](C(O)=O)[N:4]([CH3:10])[N:3]=1.C1(P([N:25]=[N+]=[N-])(C2C=CC=CC=2)=O)C=CC=CC=1.[C:28]([OH:32])([CH3:31])([CH3:30])[CH3:29].C1[CH2:37][O:36]CC1>>[Cl:1][C:2]1[CH:6]=[C:5]([NH:25][C:37](=[O:36])[O:32][C:28]([CH3:31])([CH3:30])[CH3:29])[N:4]([CH3:10])[N:3]=1

Participants

5

Reactant 4

HCID 6386tert-ButanolHCID 8028TetrahydrofuranHCID 199401P,P-Diphenylphosphinic azideHCID 189704593-chloro-1-methyl-1H-pyrazole-5-carboxylic acid

Product 1

HCID 699151145-(Boc-amino)-3-chloro-1-methyl-1H-pyrazoleYield 74%

Conditions

Temperature
70 °C

Procedure

To a solution of 3-chloro-1-methyl-1H-pyrazole-5-carboxylic acid (2.0 g, 12.46 mmol) in THF (20 ml) was added Net3 (2.60 ml, 18.68 mmol) and diphenyl phosphoryl azide (5.14 g, 18.68 mmol) at 0° C. The mixture was stirred at it for 16 h and then, tert butanol (2.4 ml, 24.9 mmol) was added and the mixture heated at 70° C. for 9 h. Then, the solvents were removed under reduced pressure and the residue purified by column chromatography (eluent 60% hexane in EtOAc) to yield 2.13 g (74%) of the title compound. [1H-NMR (DMSO-d6, 360 MHz) δ 9.55 (br. s, 1H), 6.10 (d, 1H), 3.58 (s, 3H), 1.44 (s, 9H); HPLC-MS RtJ=0.93 min; [M+H]+=232.2, 234.2]

Workup

  1. customThen, the solvents were removed under reduced pressure
  2. customthe residue purified by column chromatography (eluent 60% hexane in EtOAc)

Sources & evidence

ORD record
ord-d4017d9f6ea6457c92f2215e30452fed
Source dataset
uspto-grants-2014_06
Patent number
US08742106B2

Linked notes

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