Baclofen synthesis

5synthesis methods

Product Name:Baclofen
CAS Number:1134-47-0
Molecular formula:C10H12ClNO2
Molecular Weight:213.66

Baclofen, 4-amino-3-(4-chlorophenyl)butyric acid (15.3.5), is synthesized in two ways. According to the first, 4-chlorobenzaldehyde is condensed with two moles of acetoacetic ester, giving the product (15.3.1), which initially undergoes alkaline hydrolysis and decarboxylation forming 3-(4-chlorphenyl)glutaric acid (15.3.2). Dehydration of this gives 3-(4-chlorophenyl)glutaric acid anhydride (15.3.3), and further treatment with ammonia gives the corresponding glutarimide (15.3.4). Reacting this with an alkaline solution of a halogen (Hofmann rearrangement) gives baclofen (15.3.6).

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1134-47-0
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Yield:1134-47-0 79.4%

Reaction Conditions:

with sodium sulfamate;sodium hypobromide at -5 - 55; for 2.16667 h;

Steps:

1e Preparation of baclofen

Intermediate 0.105 g (0.455 mol), 3.6 g (0.03 mol) of sodium sulfamate and freshly prepared sodium hypobromite solution60ml (9% ~ 12%),Stirring at -5 ~ 0 for 1.5 h, slowly warming to 20 ~ 30 ° C after stirring 20min and then heated to 50 ~ 55 ° C again, keep the temperature for 20min, thin layer identification reaction end point (developing agent: n-butanol - glacial acetic acid - water (4: 1: 1),After completion of the reaction, the mixture was cooled to room temperature, the pH was adjusted to 6 to 7 with concentrated hydrochloric acid, allowed to stand for 5 hours,The crude product was recrystallized from isopropanol-water (1: 4) and vacuum dried at 55-60 ° C for 6 h to give 77.2 g of baclofen, a white medicinal complex with a clinical yield of 79.4%

References:

CN106187794,2016,A Location in patent:Paragraph 0026

22518-27-0 Synthesis