Reaktion #45025

Reaktionsgleichung

HCl

N,N-diethylethanamine

tert-butyl 5-amino-3-[2-(3-methoxyphenyl)ethyl]pyrazole-1-carboxylate

6-Bromopyridine-3-carboxylic acid

oxalyl chloride

→

6-chloro-N-[5-[2-(3-methoxyphenyl)ethyl]-2H-pyrazol-3-yl]pyridine-3-carboxamide

Ausbeute 17.3%

Lösungsmittel

DMF

2-propanol

DCM

2-propanol

methanol

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe reaction was stirred for 2 h
2. 2
   Waschenwashed with water, brine
3. 3
   Trocknendried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Sonstigeevaporated
6. 6
   Sonstigeto give the crude Boc-protected compound as a yellow gum
7. 7
   workup.STIRRINGThe solution was stirred at ambient temperature overnight
8. 8
   Sonstigewas then evaporated to dryness
9. 9
   WaschenThe column was washed with methanol
10. 10
    Waschenthe product eluted with 2N ammonia in methanol
11. 11
    Sonstigeto give an orange solid

Vorschrift

6-Bromopyridine-3-carboxylic acid (122 mg, 0.82 mmol, 1.3 eq) was dissolved in DCM (5 mL) and oxalyl chloride (72 μL, 0.82 mmol, 1.3 eq) was added dropwise followed by a drop of DMF. The reaction was stirred for 1 h at ambient temperature, then N,N-diethylethanamine (1 mL, 1.89 mmol, 3 eq) was added followed by tert-butyl 5-amino-3-[2-(3-methoxyphenyl)ethyl]pyrazole-1-carboxylate (200 mg, 0.63 mmol, 1 eq). The reaction was stirred for 2 h, then diluted with DCM and washed with water, brine, dried (MgSO4), filtered and evaporated to give the crude Boc-protected compound as a yellow gum. The gum was dissolved in 2-propanol (5 mL) and a solution of 6M HCl in 2-propanol (4 mL) was added. The solution was stirred at ambient temperature overnight and was then evaporated to dryness and loaded onto a SCX-2 column. The column was washed with methanol and the product eluted with 2N ammonia in methanol to give an orange solid. Trituration with a small volume of methanol gave 6-chloro-N-[5-[2-(3-methoxyphenyl)ethyl]-2H-pyrazol-3-yl]pyridine-3-carboxamide (39 mg, 17%) as a white solid; 1H NMR (400.13 MHz, DMSO) δ 2.89 (4H, s), 3.74 (3H, s), 6.46 (1H, s), 6.75 (1H, m), 6.81 (2H, m), 7.20 (1H, t), 7.65 (1H, d), 8.35 (1H, m), 8.95 (1H, d), 10.99 (1H, s), 12.23 (1H, s) MS m/z 357 (MH+)

Quelle