一二三四区视频,亚洲少妇熟女色,日本久热无码视频网,欧美国产日韩大尺度,亚洲a视频,久久少妇一区二区,日韩999无码视频,刺激久久久久久久,啊啊啊啊不要啊在线

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
010-86108875
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 D-Cycloserine
68-41-7

D-Cycloserine synthesis

5synthesis methods
Cycloserine, 4-amino-3-isoxalidinone (34.1.19), can be synthesized both biosynthetically from the actinomycetes Streptomyces garyphalus, Streptomyces orchidaceus, and Streptomyces lavenduale as well as synthetically from the methyl ester of D-serine, the hydroxyl group of which is replaced with a chlorine atom when reacted with phosphorous pentachloride, and subsequent reaction of the resulting product (34.1.19) with hydroxylamine results in heterocyclization to the desired cycloserine (34.1.20).

-

Yield:68-41-7 315 mg

Reaction Conditions:

with water;sodium hydroxide in methanol;dichloromethane at 20; for 4 h;

Steps:

(c) Synthesis of compound 6 from compound 3:

Sodium methoxide (12.27 mmol) in MeOH was added to a solution of hydroxylamine hydrochloride (465 mg, 6.69 mmol) in MeOH (10 mL). The mixture was stirred at room temperature for 30 min and cooled to 0 °C. Then the sodium chloride was filtered. A solution of compound 3 (1.2 g, 5.58 mmol) in CH3CN (20 mL) was added to the filtrate at 0 °C. The mixture was stirred at 0 °C for 4 h and concentrated under reduced pressure. Et3N (1.16 mL, 8.37 mmol) and CH2Cl2 (30 mL) was added to the mixture and stirred at 0 °C for 10 min. Methanesulfonyl chloride (0.73 g, 6.14 mmol) was added next, and the mixture was stirred at 0 °C for 1 h. DBU (1.27 g, 8.37 mmol) was added to the mixture at 0 °C and stirred at room temperature for 2 d. After NaOH (1.12 g, 27 mmol) in water (20 mL) and MeOH (20 mL) were added, the mixture was stirred at room temperature for 4 h. 50 mL of ethanol/isopropyl alcohol was added. The precipitate salts were filtered, and the filtrated was cooled to 0 °C in the ice bath. Glacial acetic acid was added dropwise to the well-stirred mixture to reach pH 6.0 and gave a colorless solid. The crystalline precipitate was filtered and washed twice with 1:1 ethanol/isopropyl alcohol and diethyl ether to give d-4-amino-3-isoxazolidinone (315 mg, 55%). mp 146-148 °C; +110 (c 1.0, H2O); 1H NMR (DMSO-d6, 300 MHz) δ 4.38 (t, 1H), 3.51 (m, 2H); 13C NMR (DMSO-d6, 75 MHz) δ 174.5, 75.1, 53.6; HRMS (ESI) m/z (M+H)+ calcd for C3H6N2O2 = 102.0919, found 102.0743.

References:

Kim, Hee-Kwon;Park, Kyoung-Joo Jenny [Tetrahedron Letters,2012,vol. 53,# 13,p. 1668 - 1670] Location in patent:experimental part

D-Cycloserine Related Search:

荥阳市| 前郭尔| 无锡市| 吉木乃县| 深圳市| 江津市| 沙坪坝区| 景宁| 伊宁县| 梅州市| 凤城市| 高雄市| 连平县| 北辰区| 丹江口市| 高邑县| 沈丘县| 峨山| 通山县| 玛曲县| 兴宁市| 天水市| 宁南县| 越西县| 德令哈市| 察哈| 方山县| 调兵山市| 扶沟县| 神农架林区| 象州县| 远安县| 五指山市| 松潘县| 定结县| 青河县| 白玉县| 许昌市| 仙居县| 徐州市| 特克斯县|