1-Methylpiperazine → Methyl α-[[(4-methyl-1-piperazinyl)sulfonyl]methyl]benzenepropanoate

Participants

Reaction Conditions

Reaction Steps

To a 1 L round bottom flask was added the resultant compound from Example 3E (84.5 g, 0.305 mol) and dichloromethane (305 mL). The mixture was cooled to 0° C. in an ice water bath and a solution of N-methyl piperazine (35.5 mL, 32.1 g) dissolved in dichloromethane (305 mL) was added dropwise with vigorous stirring over 90 min. After the addition was completed, the ice-water bath was removed and the mixture was stirred an additional 4 h while warming to ambient temperature. The solution was then poured into a separatory funnel containing 1 L of a 5% aqueous NaOH solution. The layers were partitioned and the organic layer was dried over potassium carbonate. Concentration in vacuo yielded an oil, which was filtered through 200 g of silica gel using 4:1 hexane/ethyl acetate as an eluant. Concentration gave 84.3 g (81%) of the desired product as a yellow oil: IR (film); 1735, 1165, 955 cm-1 ; 1H NMR (CDCl3) δ2.30 (s, 3H), 2.42 (t, 4H, J=4.8), 2.88 (dd, 1H, J=7.7, 14.0), 2.93 (dd, 1H, J=3.7, 14.0), 3.06 (dd, 1H, J=7.0, 13.6), 3.18-3.27 (m, 5H), 3.43 (dd, 1H, J=8.82, 13.9), 3.67 (s, 3H), 7.14-7.17 (m, 2H), 7.24-7.34 (m, 3H); 13C NMR (75 MHz, CDCl3) δ37.91, 42.22, 45.36, 45.83, 49.61, 52.21, 54.36, 127.06, 128.66, 128.92, 129.06, 136.79, 173.33.

Provenance & Evidence