methyl (2R)-2-amino-3-hydroxypropanoate

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

Procedure: (R)-N-isobutylserine methyl ester HCl salt was made from (D)-serine methyl ester as described in Method B3a. The ester was reacted with SOCl2, followed by 2-methyl-4-nitrophenyl isothiocyanate according to Method C2a to afford (4S)-2-(2-methyl-4-nitrophenylimino)-4-(methoxycarbonyl)-3-isobutyl-1,3-thiazolidine HCl salt.

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

Procedure: (R)-N-isobutylserine methyl ester HCl salt was made from (D)-serine methyl ester as described in Method B3a. The ester was reacted with SOCl2, followed by 2-methyl-4-nitrophenyl isothiocyanate according to Method C2a to afford (4S)-2-(2-methyl-4-nitrophenylimino)-4-(methoxycarbonyl)-3-isobutyl-1,3-thiazolidine HCl salt.

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

Procedure: (R)-N-isobutylserine methyl ester HCl salt was made from (D)-serine methyl ester as described in Method B3a. The ester was reacted with SOCl2, followed by 2-methyl-4-nitrophenyl isothiocyanate according to Method C2a to afford (4S)-2-(2-methyl-4-nitrophenylimino)-4-(methoxycarbonyl)-3-isobutyl-1,3-thiazolidine HCl salt.

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

Procedure: Another method for the preparation of Lacosamide of Formula-I was described in the Journal Bioorganic & Medicinal Chemistry, 16(19), 8968-8975 (2008), wherein D-serine methyl ester is treated with diethoxytriphenylphosphorane to give 9:1 mixture of (R)-aziridine-2-carboxylic acid methyl and ethyl ester of Formula-XIV. The mixture of compound of Formula-XIV on acetylation with acetic anhydride in the presence of triethylamine and dimethylaminopyridine gives a mixture of (R)-1-acetylaziridine-2-carboxylic acid methyl and ethyl ester of Formula-XV. The mixture of compound of Formula-XV is treated with methanol in the presence of borontrifluoride etherate BF3.Et2O to give a mixture of (2R)-2-acetamido-3-methoxypropanic acid methyl and ethyl ester of Formula-XVI. The compound of Formula-XVI on hydrolysis with lithium hydroxide yields the compound (2R)-2-acetamido-3-methoxypropanoic acid of Formula- XVII; which on reaction with benzylamine in presence of tetrahydrofuran and 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride followed by purification of the product using flash column chromatography (10:90 MeOH/CHCl3) yields compound Lacosamide of Formula-I. The reaction sequence is as given in Scheme-4; to give gives The mixture of compound of Formula-XV to give

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

Procedure: To a solution of D-Ser-OMe (LXXXVIII) in dry DCM was added TEA (1.2 eq). After the solution became clear, trityl chloride (1 eq in dry DCM) was added dropwise and stirred for 2 hours. The reaction mixture was washed with 2M HCl, brine and dried over anhydrous MgSO4. The solvent was removed under reduced pressure to give the crude product as a colorless oil. The oil crystallized from Et2O/hexane to produce pure (R)-methyl 3-hydroxy-2-(tritylamino)propanoate (LXXXIX) as white solid (85% yield). The reaction mixture was washed with 2M HCl, brine dried over anhydrous MgSO4 The solvent was removed under reduced pressure to give the crude product as a colorless oil The oil crystallized from Et2O/hexane

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

Procedure: (R)-N-isobutylserine methyl ester HCl salt was made from (D)-serine methyl ester as described in Method B3a. The ester was reacted with SOCl2, followed by 2-methyl-4-nitrophenyl isothiocyanate according to Method C2a to afford (4S)-2-(2-methyl-4-nitrophenylimino)-4-(methoxycarbonyl)-3-isobutyl-1,3-thiazolidine HCl salt.