Reaction #1483091

Reaction equation

DDAIP

4

dodecyl 2-(dimethylamino)propanoate

ethane sulfonic acid

→

dodecyl 2-(dimethylamino)propanoate ethane sulfonate salt

Yield 98.4%

Solvents

ethyl acetate

Conditions

Workup

1. 1
   workup.ADDITIONAfter addition
2. 2
   ConcentrationThe reaction mixture was concentrated under vacuum
3. 3
   Otherflushed with hexane
4. 4
   workup.STIRRINGstirred at RT for 2 h (No solid)
5. 5
   workup.WAITThe obtained sticky solid kept in deep freezer for 12 h

Procedure

A stirred solution of DDAIP base 4 (85 g, 298 mmol) in ethyl acetate (600 mL) was cooled to 0° C., then ethane sulfonic acid 20 (32.79 g, 298 mmol) was added in one lot. After addition, the temperature of the reaction mixture was slowly raised to RT, stirred at RT for 12 h and the reaction mixture was monitored by TLC. The reaction mixture was concentrated under vacuum and flushed with hexane. The obtained residue was taken in n-hexane (200 mL) and stirred at RT for 2 h (No solid). The obtained sticky solid kept in deep freezer for 12 h to afford dodecyl 2-(dimethylamino)propanoate ethane sulfonate salt (21, Nex-30) (116 g, yield: 98.4%) as a hygroscopic solid, Mp: 45-50° C. 1H-NMR (400 MHz, CDCl3): δ 0.9 (t, 31H), 1.3 (m, 18H), 1.35 (t, 3H), 1.7 (d, 31H), 1.8 (q, 21H), 2.9 (q, 2H), 3 (m, 6H), 4.2 (m, 2H), 4.2 (m, 1H); LCMS: 286 (M++1); HPLC: 99.47%.

Source