Spirobarbiturates

The structure of this compound is confirmed by the preparation of the 1-acetyl derivative, acid degradation to 4-methylquinoxalin-3-one-2-carboxylic acid (12), and alternative synthesis from the acid chloride of (12) and AW -dimethyluread A most unusual cyclization occurs when AW-dimethyl-o-phenylenediamine (15) is treated with alloxan in ethanolic solution this apparently involves an A-methyl group and leads to the formation of the spirobarbituric acid (16). The struc-... 

Si,Si-Dimethyl-Sila-Substituted Derivatives of Spirobarbiturates with Narcotic Activity... 

Bose et al. [74] have investigated the novel synthetic route for the preparation of spirobarbiturates-a class of compounds known for their interesting physiological activity. The synthesis of spiro-fi-lactams 3 (Scheme 1) was achieved by the reaction of 4,4-dicarboxy-/V-phenylazetidin-2-one 1 with carbodiimides 2 in tetra-hydrofuran. 

Scheme 1 Preparation of spirobarbiturates using 4,4-dicarboxy-/V-phenylazetidin-2-one and carbodiimides...

A series of silicon-containing spirobarbiturates 58 has been synthesized from 3,3-di(ethoxycarbonyl)-l-silacycloalkanes 57, prepared from chlor-omethyl(3-chloropropyl)silanes 56 and diethyl malonate in the presence of sodium ethylate, and urea or thiourea (64JMC695) (Scheme 12). Analogous silacycloheptyl derivatives were prepared from (4-chlorobutyl)chloro-methylsilanes similarly. 

Two resonance signals for JV-methyl groups in the spirobarbiturate 16 are also observed as a result of the long-range magnetic effect of the p-nitrophenyl moiety.112... 

Spirobarbiturates are of interest as inhibitors of dihydro-orotate dehydrogenase enzyme system (DHODase) <90JCS(P1)3137>. 

Spirobarbituric acids. A mixture of spirotetrahydropyran-4,5-barbituric acid, -phosphoric acid, and KI vigorously shaken at 135° for 10 hrs. 5,5-bis-... 

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