天堂网亚洲,天天操天天搞,91视频高清,菠萝蜜视频在线观看入口,美女视频性感美女视频,95丝袜美女视频国产,超高清美女视频图片

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List Methyl 2-Aminothiazole-4-carboxylate
118452-04-3

Methyl 2-Aminothiazole-4-carboxylate synthesis

7synthesis methods
A solution of methyl 3-bromo-2-oxo-propanoate (10 g, 51 mmol) and thiourea (4.0 g, 552 mmol) in EtOH (200 mL) was added CuOAc (0.3 g, 2.62 mmol), then stirred at room temperature for 10 h. The mixture was concentrated to give the crude product (16 g). The crude product was basified with NaHC03 to pH=8, then extracted with EtOAc (200 mL x 3). The organic layer was washed with H20 (100 mL) and brine (100 mL), and then dried over anhydrous Na2S04, and then concentrated to give the product Methyl 2-Aminothiazole-4-carboxylate (8.0 g) as a yellow solid.
-

Yield:118452-04-3 45%

Reaction Conditions:

in methanol at 0; for 1 h;Cooling with ice;

Steps:

3.2

A mixture of 2-amino-thiazole-4-carboxylic acid ethyl ester (38 g, 221 mmol) in methanol (400 mL) was cooled in an ice bath and to it was added 25% sodium methoxide over 30 minutes. The ice bath was removed after 30 minutes. A few small particles were filtered off and to this yellow solution was added saturated aqueous ammonium chloride and it was concentrated to remove excess methanol. The mixture was adjusted to pH=9.0 with sodium bicarbonate and extracted using 1:1 ether/tetrahydrofuran (3×200 mL). The combined organic extracts were washed with water, dried over sodium sulfate and concentrated to give a pale yellow solid which still contained some solvent. It was taken into hexanes, filtered on a 5.5 cm funnel then dried in vacuo to give 2-amino-thiazole-4-carboxylic acid methyl ester as a pale yellow solid (15.6 g, 45%).

References:

US2006/63814,2006,A1 Location in patent:Page/Page column 28

Methyl 2-Aminothiazole-4-carboxylate Related Search: