Reaktion #569281

Reaktionsgleichung

1H-pyrazole-1-carboxamidine hydrochloride

2-Chlorobenzenesulfonic acid 3 -[[1-N-(tert-butoxycarbonyl)piperidin-4-yl]methoxy]-5-carbomethoxyphenyl ester

trifluoroacetic acid

1H-pyrazole-1-carboxamidine hydrochloride

→

solid

Ausbeute 20.2%

2- Chlorobenzenesulfonic acid 3-[[1-(aminoiminomethyl)piperidin-4-yl]methoxy]-5-carbomethoxyphenyl ester

Ausbeute 20.2%

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent was evaporated
2. 2
   Sonstigethe residue was azeotroped with acetonitrile (2 times)
3. 3
   workup.DISSOLUTIONThe residue was dissolved in methanol (3 mL)
4. 4
   workup.STIRRINGwas stirred for 6 h
5. 5
   SonstigeThe solvent was evaporated to dryness
6. 6
   SonstigeThe residue was triturated with hexane and ether
7. 7
   workup.DISSOLUTIONThe residue was dissolved in acetonitrile
8. 8
   workup.ADDITIONdiluted with diethylether
9. 9
   Sonstigeto produce a crystalline crop, which
10. 10
    Filtrationwas collected by filtration

Vorschrift

2-Chlorobenzenesulfonic acid 3 -[[1-N-(tert-butoxycarbonyl)piperidin-4-yl]methoxy]-5-carbomethoxyphenyl ester (0.14 g, 0.26 mmol), as prepared in the preceding step, was treated with 2.5 mL of 25% trifluoroacetic acid in methylene chloride at ambient temperature for 15 min. The solvent was evaporated, the residue was azeotroped with acetonitrile (2 times), and placed under high vacuum. The residue was dissolved in methanol (3 mL) and treated with 1H-pyrazole-1-carboxamidine hydrochloride (0.057 g, 0.39 mmol) and N,N-duisopropylethylamine (0.136 mL, 0.78 mmol). The reaction mixture was stirred at ambient temperature overnight. An additional portion of 1H-pyrazole-1-carboxamidine hydrochloride (10 mg) was added to the reaction mixture and then was stirred for 6 h. The solvent was evaporated to dryness. The residue was triturated with hexane and ether. The residue was dissolved in acetonitrile and diluted with diethylether to produce a crystalline crop, which was collected by filtration to give 25.3 mg of solid. 1H-NMR (CDCl3 ; 300 MHz): δ 1.44-1.55 (m, 2H), 1.95-2.1 (m, 3H ), 3.11 (t, 2H ), 3.81 (d, 2H), 3.87 (s, 3H), 4.07 (d, 2H), 6.90 (t, 1H), 7.38 (m, 5H), 7.64 (m, 2H), 7.96 (m, 1H). Mass spectrum MADLDI-TOF) calcd. for C21H24N3O6SCl: 482.1 (M+H). Found 483.5.

Quelle