198544-26-2

Upstream product

• 90991-20-1 4-(3-nitro-phenyl)-4-oxo-butyric acid methyl ester 
• 6328-00-3 4-(3-nitro-phenyl)-4-oxo-butyric acid 

Downstream Products

• 198544-29-5 4-{3-[Bis-(2-hydroxy-ethyl)-amino]-phenyl}-4,4-difluoro-butyric acid methyl ester 
• 198544-30-8 4-{3-[Bis-(2-chloro-ethyl)-amino]-phenyl}-4,4-difluoro-butyric acid methyl ester 
• 198544-28-4 4-(3-Amino-phenyl)-4,4-difluoro-butyric acid methyl ester 

Relevant academic research and scientific papers

Synthesis of 4-[3′-bis(2″-chloroethyl) aminophenyl] -4,4-difluorobutanoic acid [4,4-difluoro-meta-chlorambucil]

The synthetic sequence to make 4-[4′-bis(2″-chloroethyl)aminophenyl]-4,4-difluorobutanoic acid {4,4-difluorochlorambucil} was not taken beyond the intermediate stage involving methyl 4,4-difluoro-4-(4′-aminophenyl) butanoate, since this amine was hydrolytically unstable. Reaction of methyl 4-(3′-nitrophenyl)-4-oxobutanoate with sulfur tetrafluoride, followed by hydrogenation, afforded the stable isomer, methyl 4,4-difluoro-4-(3′-aminophenyl)butanoate. Bis(hydroxyethylation) by treatment with oxirane, conversion of OH to Cl by Ph3P/ CCl4, and then hydrolysis of the ester group, gave 4-[3′-bis(2″-chloroethyl)aminophenyl]-4,4-difluorobutanoic acid {4,4-difluoro-meta-chlorambucil}.