Carbamic acid, N-[3-(4-methyl-1-piperazinyl)-3-oxopropyl]-, 1,1-dimethylethyl ester synthesis

Yield:1616684-41-3 70%

Reaction Conditions:

with benzotriazol-1-ol;dicyclohexyl-carbodiimide in tetrahydrofuran at 0 - 20; for 4 h;

Steps:

6 General procedure for the synthesis of 12a-12j

General procedure: Amino acids (10a-10j) were converted to the corresponding Boc derivatives (11a-11j) in quantitative yields by using di-tertbutylpyrocarbonate.¹⁸ To a solution of (11a-11j; 2 mmol) in10 mL THF, 1-hydroxybenzotriazole (HOBt; 2.2 mmol) was added. The reaction mixture was stirred for 2 min at 0 °C. The N-methylpiperazine (3 mmol) was added to above reaction mixture, followed by addition of dicyclohexylcarbodimide (DCC; 2.2 mmol,1.0 mL THF) at 0 °C.¹⁰ The reaction mixture was allowed to reach at room temperature and was stirred for next 4 h. The dicyclohexylurea (DCU) was filtered and the filtrate was evaporated under reduced pressure. The oily residue was dissolved in chloroform, organic layer was washed with 5% aqueous sodium bicarbonate followed by washing with water and finally with brine. The organic layer was dried over anhydrous Na₂SO₄ and evaporated under reduced pressure. The crude product was purified over silica gel column to afford compounds (12a-12j) in good yields.

References:

Sinha, Manish;Dola, Vasanth R.;Agarwal, Pooja;Srivastava, Kumkum;Haq, Wahajul;Puri, Sunil K.;Katti, Seturam B. [Bioorganic and Medicinal Chemistry,2014,vol. 22,# 14,p. 3573 - 3586]