L-Lactic Acid → (2S)-2-(Acetyloxy)propanoic acid
Reaction equation
[OH:1][C@@H:2](C)[C:3](N1CCNCC1)=O.[OH:12][C@@H:13]([CH3:17])[C:14]([OH:16])=[O:15]>>[C:2]([O:12][C@@H:13]([CH3:17])[C:14]([OH:16])=[O:15])(=[O:1])[CH3:3]Participants
Procedure
Scheme 3 shows the synthesis of intermediate, oxalate salt of (S)-2-hydroxy-1-(piperazin-1-yl)propan-1-one V from (S)-2-hydroxypropanoic acid (L-lactic acid) 1. Acetylation of 1 gave (S)-2-acetoxypropanoic acid 2, followed by treatment with a chlorinating reagent, such as oxalyl chloride, to give acid chloride, (S)-1-chloro-1-oxopropan-2-yl acetate 3 (Example 6). Reaction of 3 with the dihydrochloride salt of 1-benzylpiperazine in dichloromethane in the presence of triethylamine gave (S)-1-(4-benzylpiperazin-1-yl)-1-oxopropan-2-yl acetate 4 (Example 7). Hydrolysis of the acetate of 4 with lithium hydroxide gave (S)-1-(4-benzylpiperazin-1-yl)-2-hydroxypropan-1-one 5 (Example 8), followed by hydrogenation to remove the N-benzyl group to give (S)-2-hydroxy-1-(piperazin-1-yl)propan-1-one 6 (Example 9). The oxalate salt was formed from 6 with oxalic acid in ethanol and tetrahydrofuran to give V (Example 9).
Sources & evidence
- ORD record
- ord-7a8876b6814547ff9bd5643d2482ad18
- Source dataset
- uspto-grants-2014_11
- Patent number
- US08895729B2
Reaction notes
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