Ethyl-2- Methylthio Thiazole

A suspension of 0.15 mol of sodamide in 175 ml of liquid ammonia is prepared as described in Chap. I, Exp. 7. A mixture of 0.10 mol (13.1 g) of 2-methylthio-thiazole (see Exp. 52) and 30 ml of Et20 is added dropwise over 5 min. Subsequently 0.25 mol (27.3 g) of ethyl bromide is introduced over 20 min and stirring is continued for an additional 30 min. The remainder of the ammonia is then removed by placing the flask in a water bath at 35 °C. Water (200 ml) is added and 

A mixture of 0.06 mol of butyllithium, 40 ml of hexane and 45 ml of THF (see Exp. 2) is cooled to —15 °C and 0.05 mol (7.7 g) of thienothiopyran (exp. 50) is added over 5 min. After this addition the cooling bath is removed and the temperature is first allowed to rise to — 5 °C, then the solution is cooled to — 30 °C, and 0.07 mol (9.9 g) of methyl iodide is finally added over 2 min. The temperature is kept at — 30 °C for an additional 10 min, after which the cooling bath is removed. When the temperature has reached +10 °C, 100 ml of water is added. The aqueous layer is extracted twice with Et20. The combined organic solutions are dried over MgS04 and subsequently concentrated under reduced pressure. The remaining 

2-Methylthienothiophene is methylated in an essentially similar way to give the symmetrical dimethyl derivative. Crystallization from pentane at —20 °C gives a m.p. 78.5-79 °C. The yield is almost quantitative. 

---

Thiazoline, 2-methylthio- [Thiazole, 4,5-dihydro-2-(methylthio)-j, 82 2-Thiazoline, 2-(4-phenyl-l -bu ten-3-yl)thio-[Thiazole, 4,5-dihydto-2-[ [Mphenyl-methyl)-2-propenylj thio] -], 78 Thiazolium,7V-methyl-2-methylthio-, iodide [Thiazolium, 4,5-dihydro-3-methyl-2-(methylthio)-, iodide], 80 Thioacetic acid, trifluoro-, S-ethyl ester [Ethanethioic acid, trifluoro-,5-ethyl ester], 125 Toluene [Benzene, methyl-], 85 Toluene, p-bromo- [Benzene, l-bromo-4-methyl-], 86... 

Amino-2-(methylthio)thiazole-4-carboxylic acid ethyl ester 195 reacted with benzoyl isothiocyanate (Scheme 86) to furnish thiazolo[5,4-d]pyrimidine-2-one 196 [119],... 

Hydroxy-ethvl)-4-methyl-l,3-rhiazol [90% Sdp. 125"/4Torr (533 Pa)]1100 kann aus 5-(2-Hydroxy-ethyl)-4-mcthyl-2-methylthio-l,3-thiazol durch Behandlung mit amalgamiertem Aluminium in Methanol (20° 12 h) hergestellt werden. 

Sowohl die alkalische Hydrolyse von 8-Ethoxycarbonyl-6-ethyl-2-methansulfonyl-9-oxo-6,9-dihydro-(chinolino[6,5-d]-l,3-thiazol) als auch die oxidative Hydrolyse von 8-C.arboxy-6-ethyl-2-methylthio-9-oxo-6,9-dihydro- ergeben mit 83% 8-Carb-oxy-6-ethyl-2-hydroxy-9-oxo-6,9-dihydro-(chinolino[6,5-d -l, 3-thiazul (Schmp. > 300°)549 ... 

Ethyl 3-(methylthio) propionate Trimethyl thiazole C6H9N3O2 DL-Histidine L-Histidine... 

---