TERT-BUTYL 4-(4-CARBAMOYLPHENYL)PIPERAZINE-1-CARBOXYLATE synthesis

Yield:1092481-51-0 85%

Reaction Conditions:

Stage #1: 4-(4-(1,1-dimethylethoxycarbonyl)piperazin-1-yl)benzoic acidwith benzotriazol-1-ol;1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride in N,N-dimethyl-formamide at 20; for 0.5 h;
Stage #2: with ammonia in N,N-dimethyl-formamide at 0 - 20; for 20.1667 h;

Steps:

A4.b

b) Preparation of intermediate 12; A mixture of intermediate 11 (6.7 g, 0.0220 mol), N'-(ethylcarbonimidoyl)-iV,jV- dimethyl-l,3-propanediamine, monohydrochloride (4.79 g, 0.0250 mol), 1-hydroxy- lH-benzotriazole (3.38 g, 0.0250 mol) and DMF was stirred at room temperature for 30 minutes. Nη3 was passed through the solution for 5 minutes (cooling with ice) and the mixture was stirred at room temperature for 18 hours. NH3 was passed again for 5 minutes through the solution and the mixture was stirred for 2 hours at room temperature. H₂O (50 ml) was added and the product was precipitated. The product was filtered off, washed with water and dried, yielding 5.77 g (85 %) of intermediate 12.

References:

WO2008/148840,2008,A1 Location in patent:Page/Page column 67