Methylsuccinic anhydride

Methylsuccinic anhydride is prepared by condensation of ethyl 2-bromopropionate with ethyl cyanoacetate followed by hydrolysis of the nitrile, decarboxylation of the resultant p-ketoacid, and dehydration. 

Alternative methods of preparing the starting acids can be used, but are generally less convenient. Benzo[6 ]thiophene derivatives were prepared from 2-methyl-3-(2 -thenoyl)propionic acid, which was obtained either by reacting 2-thienylmagnesium iodide with methylsuccinic anhydride, or by coupling 2-bromoacetylthiophene with the sodium salt of diethyl methylmalonate (45JA1645). 

Another isomeric acid is obtained from bromtri-methylsuccinic anhydride it is probabljy an unsaturated acid,the formula for the brom-anhydride perhaps being qqch... 

Friedel-Crafts aeylatwn. Substitution of nitroethane for the less volatile nitrobenzene in the Friedel Crafts reaction of / -xylene with methylsuccinic anhydride... 

Methylpodocaipic acid, 42 Methyl propiolate, 547 Methyl propynoate, 220 N-Methylpyrrolidine, 345, 355,462,463 Methyl sterculate, 436 a-Methylstyrene, 493 /3-Methylstyrene, 71, 292 Methylsuccinic anhydride, 357... 

Enolates of succinic and methylsuccinic anhydride can be generated using the highly hindered base (33), previously reported to be capable of reacting specifically with esters and methyl ketones while aldehydes are ur aflfected. Coupling of such enolates with aldehydes leads to 3-methoxycarbonyl-4-substituted butyrolactones (34) in yields generally above 70%. 

S)-Methylsuccinic anhydride was produced with 99% ee when the carbonylation was performed at 55 °C. At 80 °C, some product racemization occurred. 

Methylstyrene, MA copolymerization, 373, 374 Methylsuccinic anhydride, hydrolysis rate, 74 3-Methylthiophene, MA copolymerization, 536 Methyl undecylenate MA ene adduct, 151, 152 MA ene reaction, 152... 

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