3-methyl-5-methylthio-2- 2,3-dihydro

CARBAMIC ACID, METHYL(METHYLTHIO)-, 2.3-DIHYDRO-2,2-DIMETHYL-7-BENZOFURANYL ESTER... 

Purine, l-methyl-2-methylthio-6-thioxo-l,6-dihydro-amination, 5, 560 Purine, 9-methyl-8-phenyl-dipole moments, 5, 521 Purine, 9-methyl-8-phenyl-6-thiomethyl-dipole moments, 5, 521 Purine, 6-methylsulfonyl-synthesis, 5, 597... 

To a solution of methyl 3-oxobutanoate 127 (580 mg, 5 mmol) and l-methyl-2-methylthio-l//-imidazole-5-carboxaldehye 128 (390 mg, 2.5 mmol) in 5 mL of absolute methanol was added a solution of ammonium hydroxide (25%, 0.4 mL). The reaction was heated at reflux overnight before cooling to room temperature and removing the solvent. The crude product was purified by preparative TLC to afford 526 mg of dimethyl l,4-dihydro-2,6-dimethyl-4-(l-methyl-2-methylthio-5-imidazolyl)-3,5-pyridine-dicarboxylate 129 (60%) as a solid, mp = 200-201 °C (MeOH). 

Treatment of ethyl 10-methylthio-9-fluoro-3-methyl-2,3-dihydro-7-oxo-7//-pyrido[l,2,3- 7e]-l,4-benzoxazine-6-carboxylate with oxone in aqueous MeOH at 0°C afforded 10-methylsulfonyl derivative (99H(51)1563). Methylthio group in a 7-(4-methylthiophenyl)-5-oxo-2,3-dihydro-5//-pyrido[l,2,3- 7e]-l,4-benzoxazine-3-carboxamide was oxidized to a sulfoxide and a sulfone group (OOMIPl). 

Thiazoline, 2-methylthio [Thiazole, 4,5-dihydro-2-(methylthio)-], 82 2-Thiazolme, 2-(4-phenyl 1 buten-3-yl)thio-[Thiazole, 4,5-dihydro-2-[ [ l-(phenyl-methyl)-2-propenyl] thio] -], 78 Tluazolium,. V-inethyl-2-methylthio-,... 

Methylthio viny 1) quinoxaline Methyl 4,6,7-trimethyl-3-oxo-3,4-dihydro-... 

Examination of 37 basidiomycetous yeasts indicated formation of several sulfur volatiles 3-(methylthio)-l-propanol, methanethiol (MT), S-methyl thio-acetate, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), allyl methyl sulfide and 4,5-dihydro-3(2//)-thiophenone. The component produced in the largest amounts, 40 100 mg L-1, was 3-(methylthio)-l-propanol29 Cheeseripening yeasts are considered later (Section 11.1.2.4.5). 

Contrasting with the reported formation of fused [l,3,4]thiadiazole rings in the course of the reaction of 3-substituted-4-amino-5-thio-47/-[l,2,4]triazoles 83 with various isothiocyanates (cf. Section 11.07.8.3, Table 3), the reactions with methyl isothiocyanate and with phenylisocyanate afford 3,7-disubstituted-6,7-dihydro-57/-[l,2,4]triazolo[4,3-f] [l,2,4]triazole-6-thiones 110 and -triazole-6-ones 111, respectively (Equation 29) <1986MI607, 1992IJB167>.The same reaction of 4-amino-l-methyl-3,5-bis(methylthio)[l,2,4]triazolium iodide 112 with aryl isothiocyanates yields the mesoionic compounds 113 (Equation 30) <1984TL5427, 1986T2121>. 

A mixture of l-methyl-2-methylthio-4,5-dihydro-l //-imidazole and diethyl malonate was heated for 54 hr to give diethyl (1 -methyl-2-imidazolidi-nylidene)malonate (471, R = H, R1 = Et) in 56% yield (86CB2208). 

Dimethyl malonate was added to a suspension of sodium hydride in THF at room temperature, and after 10 min, 2-methylthio-l-methylquinolinium iodide was added. The reaction mixture was stirred for 1.5 hr at ambient temperature to give dimethyl (1 -methyl-1,2-dihydro-2-quinolinyIidene)ma-lonate in 95% yield [81 H( 15)277]. 

Chloro- and 2-methylthio-l-methylquinolinium iodides were reacted with dimethyl malonate in the presence of l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in DMF at 80°C for 1 hr, or in the presence of triethylamine for 5 hr, to afford dimethyl (1 -methyl-l,2-dihydro-2-quinolinylidene)malonate (86MI3). The use of DBU and the 2-methylthio derivative gave a better yield than that from triethylamine and the 2-chloro derivative. 

Insbesondere vergleichende UV-Untersuchungen von Methylthio-1,3,4-oxadiazolen sowie 3-Methyl-2-thiono-2,3-dihydro-l,3,4-oxadiazolen und LCAO-MO-Berechnungen, die eine ho-here a-Elektronenstabilisierung der Thiono-Form ergeben, bestiiligen die Dominanz des Thio-no-Tautomeren10. 

In 2-methyl-3-methylthio-5,6-diphenyl-2,5-dihydro-l,2,4-triazine (19) the heterocyclic ring is folded at N-2 and C-5 to take a boat form with a dihedral angle between the two planes of 146.5°. The 6-phenyl ring is parallel to the plane to which it is attached, while the 3-methylthio group lies in the other plane. 

Substituted 3-thioxo-l,2,4-triazin-5-ones (76 R4 = H) are stable toward sodium amalgam, but the 4-substituted derivatives (76 R2 = H) are reduced to the 1,6-dihydro compounds (282). Hydrogenation of (76 R2 = H) affords ring-opened products. 3-Methyl-thio-l,2,4-triazin-5-ones (78) are reduced by sodium amalgam to 3-methylthio-3,4-dihydro-... 

Thione derivatives can be S-methylated. Thus the tetrahydro-1,3-oxazine-2-thione with methyl iodide yielded 2-methylthio-5,6-dihydro-4//-l,3-oxazine (47). 

IUPAC 4-amino-4,5-dihydro-3-methyl-6-phenyl-l, 2,4-triazin-5-one 4-amino-6-lert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazine-5-one N,N -diisopropyl-6-methoxy-1,3,5-triazine-2,4-diamine... 

Methyl 3,4-dihydro-2-methyl-5-methylthio-4-oxothieno[3,4-[Pg.273]

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