Succinimide, methylation

METHYL y-BROMOCROTONATE JV-Bromosuccinimide. Dissolve, with the aid of rapid mechanical stirring, 80 g. of pure succinimide (Section V,14) in a mixture of 150 g. of finely crushed ice and a solution of 32 g. of sodium hydroxide in 200 ml. of water contained in a litre beaker and cooled externally by ice. Immediately the imide has dissolved, continue the vigorous stirring and introduce 42 -5 ml. of bromine in one lot from a separatory funnel supported over the beaker it is essential that the bromine be instantly suspended in the solution. After stirring vigorously for 2 minutes, filter at the pump and... 

Methyl y-bromocrotonate. Mix 36 g. of iV-bromosuccinimide, 40 g. of methyl crotonate and 60 ml. of dry, redistilled carbon tetrachloride in a 500 ml. round bottomed flask. Reflux ou a water bath for 12 hours by this time all the sohd should have risen to the surface of the liquid. Filter off the succinimide at the pump and wash it with a little dry carbon tetrachloride. Remove the solvent on a water bath and distil the residue under reduced pressure, preferably from a Widmer flask (compare Figs. II, 24, 4-5). Collect the methyl y-bromocrotonate at 77-78°/8 mm. the yield is 31 g. 

The values of the 1-hydroxy moiety of (5)-(- -)-iVb-acetyl- 1-hydroxytrypto-phan methyl ester (32), methyl l-hydroxyindole-3-butylate (33), iVb-methoxy-carbonyl-l-hydroxytryptamine (34), 1-hydroxymelatonm (19), l-hydroxy-6-nitroindole (35), and l-hydroxy-5-nitroindole (36) are determined to be 9.8, 8.4, 8.2, 8.1, 6.9, and 6.8, respectively (Fig. 2) (2000H1881). Thus, 1-hydroxyindoles are weak acids, stronger than phenol and weaker than succinimide. Therefore,... 

Fig. 2-11. The effect of flow rate on the selectivity of a-methyl-a-phenyl succinimide on teicoplanin CSP (250 X 4.6 mm) in normal phase. The mobile phase was ethanol hexane (20/80 v/v) at ambient temperature (23 °C).

Analog erhalt man aus N-Methyl-bis-[benzyliden]-succinimid N-Methyl-3-benzyl-2-benzyliden- und N-Methyl-2,3-dibenzyl-succinimid1. 

Linz et al.6 report the synthesis of enantiomerically pure cyclosarkomycin 6, a stable crystalline precursor of sarkomycin 5. As described in Scheme 5-3, 6 can be obtained from 8, an asymmetric Diels-Alder adduct of (E )-bromoacry-late. (E)-3-bromoacrylate 9a [the acrylate of (R)-pentolactone 11] and 9b [the acrylate of ( S )-A-methyl hydroxyl succinimide 12] undergo TiCL-mediated Diels-Alder reactions giving 10a or 10b, the endo-product, with high diaster-eoselectivity (Scheme 5-4). With the key intermediate 10a in hand, synthesis of compound 6 is accomplished by following the reaction sequence shown in Scheme 5-5. 

Mit 2-3 mol N-Brom-succinimid pro mol Imidazol konnen auch zwei Brom-Atome in die Positionen 4 und 5 eingefiihrt werden662,663. Die Dibromierung von 5-Methoxycarbonyl-l-methyl-imidazol gelingt so allerdings nicht. Als einziges Reaktionsprodukt wird auch mit einem UberschuB N-Brom-succinimid in 83% Ausbeute 2-Brom-5-methoxycarbonyl-1 -methyl-imid-azol erhalten660. 

Mit N-Brom-succinimid werden Methyl-Gruppen bromiert272 z.B. ... 

Bei einer Variante dieser Reaktion erhalt man N-geschiitzte primare Allylamine, indem man das l-Phenylseleno-2-alken in Methanol mit Chloramin-T oder mit Carbamid-saure-benzylester/N-Chlor-succinimid/Triethylamin umsetzt2,4, wie hier fur die Herstel-lung von 3-Methyl-3-(4-methyl-henzolsulfonylamino)-l-buten (88%) und (2R,3E)-4-(Be-nzyloxycarbonyl-amino)-2-penten (56%) formuliert. 

Durch eine Umlagerung vom Sommelet-Hauser-Typ (vgl. S. 1149) erhalt man beim Erhitzen von N-Aryl-S,S-dimethyl-sulfiliminen in Gegenwart von Triethylamin oder an-deren Basen oder auch Succinimid 2-(Methylthio-methyl)-aniline z. B. 4-Chlor-2-(methylthio-methyl)-anilin (95%)4 bzw. 6-(Methylthio-methyl)-2-trifluormethyl-anilin ( 100%)5 ... 

Miscellaneous Compounds. A saturated spirocychc pyrrohdine serves as the nucleus for a diamine that has been described as a hypohpemic agent. Treatment of the carbanion of the substituted cylcohexane carboxyhc ester (20-1) with methyl bromoacetate leads to the alkylation and formation of the diester (20-2). Saponification of the ester groups followed by reaction with acetic anhydride leads to ring closure of the succinic anhydride (20-3). Condensation with ammonia leads to the succinimide (20-4). The side chain is then added by alkylation of the anion on nitrogen with l-bromo-4-dimethylaminobutane (20-5). Reaction of this last intermediate with lithium aluminum hydride leads to the reduction of the carbonyl groups to methylene. This affords the pyrrolidine (20-6) atiprimod [22]. 

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