取甲壳素加入420g/L (42%)氢氧化钠溶液(加少量的NaBH4),煮沸,每隔2h过滤,水洗,更换新碱液1次,继续脱乙酰基,至8h,过滤,水洗至中性,自然干燥,即得白色壳聚糖。收率10%-13%,脱乙酰度可达91%,特性粘度为790-890ml/g,相对分子质量为0.81×106-1.34×106。
在反应釜中加入THF7.5L和上步制备的化合物(S)-6-苄氧基-5-羟基-3-氧代己酸叔丁酯7.54kg(16.8mol),搅拌溶解,20~25ºC15min内加入1mol/L三乙基硼的己烷溶液40.0L(40.0mol),反应吸热.加毕,将溶液搅拌10min.然后冷却至-60ºC,立刻加入硼氢化钠(NaBH4)1.9kg(50.4mol)(反应不放热),再在-60ºC 2.5h...
CAS No. : 7440-02-0 分子式: Ni 分子量: 58.70 第二部分:成分 / 组成信息 有害物成分 含量 CAS No. 镍 7440-02-0 第三部分:危险性概述 危险性类别: 侵入途径: 健康危害: 可引起镍皮炎,又称镍“痒疹”。皮肤剧痒,后出现丘疹、疱疹及红斑,重者化脓、溃烂。长期吸入镍粉可致呼吸道刺激...
CAS No.:91-73-6 分子式:C20H19N 分子量:273.371565103531 如需查看该化合物的详细结构式,mol文件,smile,InChi 请点击:N,N-二苄基苯胺结构式 下载该化合物MOL文件:N,N-二苄基苯胺MOL PubChem CID:87566882 快速询单 N,N-二苄基苯胺的其他展现形式 ...
A solution of 13.5 g of methyl 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]- 1-oxobutyl]-α,α-dimethylphenylacetate in 250 mL of methanol was cooled in an ice-methanol bath and 1.8 g of NaBH4 was added in portions. After 1 hour, the mixture was concentrated to a solid. The ...
CAS NO:100-51-6 Molecular Formula: C7H8O Molecular Weight: 108.14 EINECS: 202-859-9 Product Categories: Industrial/Fine Chemicals;Alcohols;Aromatic;Chemical Class;ACS and Reagent Grade Solvents;ACS Grade;ACS Grade Solvents;Amber Glass Bottles;Puriss p.a.;Solvent Bottles;Solvent by Application;So...
CAS No.:1398-61-4 分子式:(C8H13NO5)N 分子量:(203.19)n 如需查看该化合物的详细结构式,mol文件,smile,InChi 请点击:几丁质结构式 下载该化合物MOL文件:几丁质MOL PubChem CID:87565262 快速询单 几丁质的其他展现形式 相关化合物 正庚基 2-乙酰氨基-3,4,6-O-三乙酰基-2-脱氧-beta-D-吡喃葡萄糖苷...
Distil I-octyne from NaBH4 to remove peroxides. Fractionate it through a 10inch Widmer column (p 11) at 125-126o/759mm [Sletzinger & Dawson J Org Chem 14 853 1949.] [Beilstein 1 III 1005, 1 IV 1034.] Check Digit Verification of cas no The CAS Registry Mumber 629-05-0 includes...
1: 950 g / NaBH4 / methanol / 0.17 h / Ambient temperature2: pyridine / 4 h / Ambient temperature3: 1) NaI / 1) DMF, 30 min, 80 deg C, 2) 30 min, 80 deg C4: 79 percent / KOH / methanol / 0.5 h / Heating5: 90 percent / PPTS / CH2Cl2 / 24 h / Ambient temperature6...
2: 97 percent / NaBH4 / aq. ethanol3: 59 percent / 2-bromo-1,3,2-benzodioxaborole, N,N-diisopropylethylamine / CH2Cl2 / 3 hView Scheme Multi-step reaction with 4 steps1: aqueous NaOH2: palladium/charcoal; methanol / 30 °C / 5884.06 Torr / Hydrogenation3: acetic acid; Al2O3 ...