Reaction #1483089

Reaction equation

DDAIP

4

dodecyl 2-(dimethylamino)propanoate

maleic acid

→

dodecyl 2-(dimethylamino)propanoate maleate salt

Yield 98.6%

Solvents

methanol

Conditions

Workup

1. 1
   workup.ADDITIONAfter addition
2. 2
   ConcentrationThe reaction mixture was concentrated under vacuum
3. 3
   Otherflushed with ethyl acetate (2×100 mL)
4. 4
   workup.STIRRINGstirred at RT for ½ h (No solid)
5. 5
   ConcentrationThe reaction mixture was concentrated under vacuum
6. 6
   workup.WAITThe obtained sticky solid was kept in deep freezer for 2 h

Procedure

A stirred solution of DDAIP base 4 (80 g, 280 mmol) in methanol (600 mL) was cooled to 0° C., then maleic acid 16 (32.48 g, 280 mmol) was added in one lot. After addition, the temperature of the reaction mixture was slowly raised to RT and stirred at RT for 12 h; the reaction mixture was monitored by TLC. The reaction mixture was concentrated under vacuum and flushed with ethyl acetate (2×100 mL). The obtained residue was taken in n-hexane (200 mL) and stirred at RT for ½ h (No solid). The reaction mixture was concentrated under vacuum. The obtained sticky solid was kept in deep freezer for 2 h to afford dodecyl 2-(dimethylamino)propanoate maleate salt (17, Nex-20) (111 g, yield: 98.6%) as a solid, mp: 65-70° C. 1H-NMR (400 MHz, CDCl3): δ 0.9 (t, 3H), 1.25 (m, 18H), 1.6 (d, 3H), 1.65 (q, 2H), 2.9 (s, 6H), 4.1 (q, 1H), 4.2 (t, 2H), 6.3 (d, 2H); LCMS: 286 (M++1); HPLC: 80.48%.

Source