docosa-2,4,6,8,10,12-hexaenoic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of docosahexaenoic acid (0.986 g, 3.0 mmol) in CH3CN (6.0 mL) was added carbonyldiimidazole (0.535 g, 3.3 mmol) in one portion at 0° C. The mixture was allowed to warm to room temperature and stirred at room temperature for 30 min. TLC showed a complete reaction (1:1 EtOAc/hexane). N,N-dimethylaminoethanol (0.89 g, 10.0 mmol) was added dropwise followed by addition of 4-dimethylaminopyridine (0.073 g, 0.60 mmol) The mixture was stirred at room temperature overnight. The solvent was removed by rotary evaporation and the residue was purified on silica gel using 72% EtOAc/hexane, 80% EtOAC/hexane and 100% EtOAc with 0.5% MeOH each to provide the product, 2-dimethylaminoethyl docosahexaenoate (1.098 g, 92%), as a light yellow oil. The product was stored at -20° C. with small amount of β-carotene. was stirred at room temperature overnight The solvent was removed by rotary evaporation the residue was purified on silica gel using 72% EtOAc/hexane, 80% EtOAC/hexane and 100% EtOAc with 0.5% MeOH

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Reaction of docosahexaenoic acid (0.10 g, 0.30 mmol) with 4-aminopyridine (0.03 g, 0.30 mmol) was conducted according to the general amide coupling procedure using DCC to obtain the product as a yellow solid (0.11 g, 91%). EIMS m/z: 405 ([M]+).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of docosahexaenoic acid (0.986 g, 3.0 mmol) in CH3CN (6.0 mL) was added carbonyldiimidazole (0.535 g, 3.3 mmol) in one portion at 0° C. The mixture was allowed to warm to room temperature and stirred at room temperature for 30 min. TLC showed a complete reaction (1:1 EtOAc/hexane). N,N-dimethylaminoethanol (0.89 g, 10.0 mmol) was added dropwise followed by addition of 4-dimethylaminopyridine (0.073 g, 0.60 mmol) The mixture was stirred at room temperature overnight. The solvent was removed by rotary evaporation and the residue was purified on silica gel using 72% EtOAc/hexane, 80% EtOAC/hexane and 100% EtOAc with 0.5% MeOH each to provide the product, 2-dimethylaminoethyl docosahexaenoate (1.098 g, 92%), as a light yellow oil. The product was stored at -20° C. with small amount of β-carotene. was stirred at room temperature overnight The solvent was removed by rotary evaporation the residue was purified on silica gel using 72% EtOAc/hexane, 80% EtOAC/hexane and 100% EtOAc with 0.5% MeOH

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-hydroxyphenyldimethylsulfomethyl sulfate 2.66 g (0.01 mol) was heated and dissolved in 40 ml of acetonitrile. Docosahexaenoic acid 3.28 g (0.01 mol) was added to the solution obtained in a stream of nitrogen, and the mixture was stirred at 0° C. To the mixture solution, dicyclohexyl carbodiimide 2.06 g (0.01 mol) was added little by little, and the solution was stirred for 2 hours at 0° C. and then for 2 hours at room temperature. The solution reacted was filtered to remove dicyclohexyl urea, and the filtrate was distilled in vacuo to obtain oily residue. D-alanine 0.89 g (0.01 mol) and triethyl amine 1.4 ml (0.01 mol) were added to 10 ml of water. An acetonitrile solution of the above oily residue was added to the mixture with stirring, and stirred for 10 hours at room temperature. After reaction, the reaction mixture was concentrated under reduced pressure. The concentrate was adjusted to pH 2 or 3 with 6N-HCl, and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried over anhydrous sodium acetate, and freed of solvent in vacuo. The oily residue obtained was purified by column chromatography (column: 2.5×15 cm) on 50 g of silica gel and N-docosahexaenoyl-D-alanine 1.6 g was obtained. obtained in a stream of nitrogen was stirred for 2 hours at 0° C. The solution reacted was filtered to remove dicyclohexyl urea the filtrate was distilled in vacuo to obtain oily residue with stirring stirred for 10 hours at room temperature After reaction the reaction mixture was concentrated under reduced pressure extracted with ethyl acetate The ethyl acetate layer was washed with water dried over anhydrous sodium acetate The oily residue obtained was purified by column chromatography (column: 2.5×15 cm) on 50 g of silica gel

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-hydroxyphenyldimethylsulfomethyl sulfate (trade name: SANCELER-DSP, manufactured by Sanshin Kagaku Kogyo Co., Ltd.) 2.66 g (0.01 mol) was heated and dissolved in 40 ml of acetonitrile. Docosahexaenoic acid 3.28 g (0.01 mol) was added to the solution obtained in a stream of nitrogen, and stirred at 0° C. To the mixture solution, dicyclohexyl carbodiimide 2.06 g (0.01 mol) was added little by little, and the solution was stirred for 2 hours at 0° C. and then for 2 hours at room temperature. The solution reacted was filtered to remove dicyclohexyl urea, and the filtrate was distilled in vacuo to obtain oily residue. D-serine 1.05 g (0.01 mol) and triethyl amine 1.4 ml (0.01 mol) were added to 10 ml of water. An acetonitrile solution of the above oily residue was added to the mixture with stirring, and stirred for 10 hours at room temperature. After reaction, the reaction mixture was concentrated under reduced pressure. The concentrate was adjusted to pH 2 or 3 with 6N-HCl, and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried over anhydrous sodium acetate, and freed of solvent in vacuo. The oily residue obtained was purified by column chromatography (column: 2.5×15 cm) on 50 g of silica gel and N-docosahexaenoyl-D-serine 1.7 g was obtained. obtained in a stream of nitrogen was stirred for 2 hours at 0° C. The solution reacted was filtered to remove dicyclohexyl urea the filtrate was distilled in vacuo to obtain oily residue with stirring stirred for 10 hours at room temperature After reaction the reaction mixture was concentrated under reduced pressure extracted with ethyl acetate The ethyl acetate layer was washed with water dried over anhydrous sodium acetate The oily residue obtained was purified by column chromatography (column: 2.5×15 cm) on 50 g of silica gel