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 L-Serine, N-[(1,1-diMethylethoxy)carbonyl]-O-Methyl-, coMpd. with N-cyclohexylcyclohexanaMine (1:1)
69912-63-6

L-Serine, N-[(1,1-diMethylethoxy)carbonyl]-O-Methyl-, coMpd. with N-cyclohexylcyclohexanaMine (1:1) synthesis

2synthesis methods
-

Yield:-

Reaction Conditions:

Stage #1: boc-β-methoxyalanine dicyclohexylaminewith hydrogenchloride in 1,4-dioxane at 0 - 20;
Stage #2: methyl chloroformatewith sodium carbonate;sodium hydroxide at 0 - 20;
Stage #3: with hydrogenchloride in water; pH=1;

Steps:

11

To Boc-O-methyl-L-serine dicyclohexylammonium salt 11a1 (Chem-lmpex) (4.5 g, 1 1.2 mmoles) in 1 ,4-dioxane at 0°C is added an 8M HCI solution in 1 ,4-dioxane and the mixture is stirred for 2 hours at RT. The reaction mixture is concentrated and co- distilled with 1 ,4-dioxane until dryness. The salt is dissolved in 1 N NaOH (22.5 ml_, 22.5 mmoles) and Na2C03 (0.6 g, 5.6 mmoles) is added at 0°C followed by dropwise addition of methyl chloroformate (0.87 ml_, 1 1.2 mmoles). The reaction mixture is stirred at RT for 3 hours. The solution is washed with ether and acidified (pH=1) with 1 N HCI. The aqueous layer is extracted with DCM and the organic layer is washed with brine, dried over Na2S04 and concentrated to afford 11a2.

References:

WO2011/91532,2011,A1 Location in patent:Page/Page column 26

江源县| 澜沧| 清涧县| 康乐县| 天镇县| 沙湾县| 奉节县| 蛟河市| 广水市| 阳春市| 黑龙江省| 乌苏市| 于田县| 邢台市| 长岛县| 澄城县| 海兴县| 澳门| 东乌珠穆沁旗| 专栏| 德令哈市| 皮山县| 四川省| 灵璧县| 新民市| 稻城县| 祁东县| 新昌县| 河北区| 库车县| 拜泉县| 区。| 洞头县| 和顺县| 丰顺县| 岳西县| 介休市| 长泰县| 宕昌县| 依兰县| 全椒县|