3- 5-methyl-2,4-oxazolidinedione

One of the standard methods for construction of the basic heterocyclic ring was elaborated not long after the turn of the century. Thus, condensation of ethyl lactate with guanidine leads to the imine of the desired ring system (47), possibly by a reaction scheme such as that outlined below. Hydrolysis affords the oxazolidinedione (48). Methylation in the presence of base gives 49. 

Benkovic and co-workers also isolated spirocyclic 2-amino-4(5/7)-oxazolones during their studies on pterin-dependent amino acid hydroxylases (Scheme 6.24). Reaction of 91 with 0-methyl hydroxylamine or semicarbazide at pH 4.8 yielded 92a and 92b, respectively. The authors showed that 92 does not simply result from reaction of the corresponding oxazolidinedione with either reagent. Further, by using H2 0 as the solvent they demonstrated that there was no incorporation into the product. Two different but precedented mechanisms were proposed to account for this rearrangement. The stereochemistry of 92b was confirmed by single-crystal X-ray. 

Doya " disclosed an improved process for preparation of 2,4-oxazohdinediones from a-hydroxy esters and urea in a recent patent. The process effects condensation of the starting materials using a metal oxide, for example, lead oxide at 100-250 °C followed by fractional distillation to recover any unreacted a-hydroxy ester. The product is then isolated by distillation. The recovered starting material can be recycled. 5-Methyl-2,4-oxazolidinedione, 212 (R = Me) was isolated in 80.4% yield of 99.4% purity in this manner. 

On the other hand, Wyeth-Ayerst chemists ° encountered limitations with this methodology during their syntheses of spirocyclic 2,4-oxazolidinediones derived from isoindole (Scheme 6.55). For example, reaction of 246 with chlorosulfonyl isocyanate followed by cyclization with potassium terf-butoxide afforded poor to modest yields of 247 when R was a substituted benzyl group. Cyclization of 246 using ethyl chloroformate (ECF), triethylamine and 4-(dimethylamino)pyridine (DMAP) in refluxing tetrahydrofuran (THF) gave 247 in only 29% yield when R was methyl and failed completely if R was an isopropyl group. However,... 

Therapeutic Function Anticonvulsant, Antiepileptic Chemical Name 2,4-Oxazolidinedione, 5-methyl-3-(2-propenyl)-Common Name Allomethadione, Aloxidone Structural Formula ... 

Chemical Name (/LS )-3-(3,5-dichlorophcnyl)-5-vinyl-l,3-oxazolidine-2,4-dione 3-(3,5-dichlorophenyl)-5-ethenyl-5-methyl-2,4-oxazolidinedione CAS Registry No 50471-44-8... 

In this chapter, oxazole and its derivatives are named and numbered as in Chemical Abstracts. Thus compound (6) is called 4,5-dihydrooxazole rather than 2-oxazoline or A2-oxazoline, (7) is 2,5-dihydrooxazole, the betaines (3) are named anhydro-5-hydroxy-oxazolium hydroxides and not oxazolium 5-oxides or oxazolium 5-olates, and the oxo derivatives (4) and (5) are 5(4//)-oxazolone and 5(2//)-oxazolone, respectively, the position of the extra hydrogen atom being indicated in parentheses. The fully saturated compound (8) is oxazolidine its oxo derivatives are named oxazolidinones and oxazolidinediones, e.g. compound (9) is 2-oxazolidinone and (10) is 4,5-oxazolidinedione. A formula such as (11) is not meant to imply that all the substituents are methyl groups it represents a general oxazolidine derivative and is used in place of the cumbersome expression (12 R-R = H, alkyl or aryl). 

Irradiation of a benzene solution of 5-phenyl Af-benzoylformyl-A-p-tolylthiocar-bamate 48a (Scheme 23) gave 5-phenyl-5-phenylthio-3-p-tolyloxazolidine-2,4-dione 49a in 61% yield accompanied by oxazolidine-2,4-dione dimer (15%), p-tolyl isocyanate (22%), and diphenyl disulfide [29]. Photolysis of 48a in the solid state gave oxazolidine-2,4-dione 49a in 96% yield. For the N-methyl derivative, 48b, compared to the solution photochemistry in which only 8% of oxazolidinedi-one 49b was obtained with a complex mixture, radical cyclization proceeds selectively to give oxazolidinedione in 75% yield in the solid state. Whereas N-p-tolyl and A-methyl derivatives, 48a and 48b, formed achiral crystals, the N-benzyl derivative 48c crystallized in chiral space group P2. Photolysis of the chiral... 

DICHLOROPHENYI.)-5-OXAZOLIDINEDIONE 3-5-METHYL-5-VINA L-2,4-VINCLOZOLIN (GERMAN)... 

N-(3,4-DICHLOROPHENYL)-N -METHYL-N -METHOXYUREA see DGD600 3-(3,5-DICHLOROPHENYL)-5-METHYL-5-VINYL-2,4-OXAZOLIDINEDIONE see RMAOOO... 

C6H9N03 3,5,5-tri methyl-2,4-oxazolidinedione 127-48-0 25.00 1.1467 2 7821 C6H10O2 trans-2-ethyl-2-butenoic acid 1187-13-9 50.00 0.9578 1... 

Oxazolidinedione, 3-(3,5-dichlorophenyl)-5-ethenyl-5-methyl- Vinclozolin 2650a ... 

Sodium derivative of 5-ethyl-5-methyl-2, 4-oxazolidinedione is obtained by refluxing urea and ethyl-a-hydroxy-a-methylbutyrate for 24 horns in the presence of sodium methoxide, due to eondensation followed by cyclization. N-methylation is carried out by treatment with dimethyl sulphate. 

Butler TC, The effects of N-methylation in 5,5-disubstituted derivatives of barbituric acid, hydantoin and 2,4-oxazolidinedione, /. Am. Ph. Assoc., 44, 367-370 (1955). NB Ofiier reported values barbital (7.8) metharbital (8.2) phenobarbital (7.3) mephobarbital (7.7) N-norhexobarbital (7.9) hexobarbital (8.3). As file values for barbital and phenobarbital are about 0.2 units less fiian the best values in the literature, the remaining values should be regarded as low by the same amount. 

Craig this value is from Butler TC, the effects of N-methylation in 5,5-disubstituted derivatives of barbituric acid, hydantoin and 2,4-oxazolidinedione, /. Am. Pharm. Assoc., 44, 367-370 (1955). 

Dichlorophenyl)-5-ethenyl-5-methyl-2,4-oxazolidinedione. See Vinclozolin 0-(2,4-Dichlorophenyl) 0-ethyl S-propyl phosphorodithioate. See Prothiofos Dichlorophenyl imidazoldioxolan CAS 85058-43-1... 

N-(3,4-Dichlorophenyl)-N -methyl-N -methoxyurea. See Linuron 3-(3,5-Dichlorophenyl)-5-methyl-5-vinyl-1,3-oxazolidine-2,4-dione 3-(3,5-Dichlorophenyl)-5-methyl-5-vinyl-2,4-oxazolidinedione. See Vinclozolin... 

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