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ChemicalBook CAS DataBase List H-TYR(BZL)-OH
16652-64-5

H-TYR(BZL)-OH synthesis

3synthesis methods
-

Yield: 62%

Reaction Conditions:

Stage #1:L-tyrosine with potassium hydroxide;copper(II) sulfate in water at 15 - 65; for 1 h;
Stage #2:benzyl chloride in water;N,N-dimethyl-formamide at 20 - 55; for 2 h;
Stage #3: with hydrogenchloride;ammoniamore than 3 stages;

Steps:

B.1
To an ice cooled solution of potassium hydroxide (40.0 g, 0.605 mol) in 100 ml of water was added L-tyrosine (50 g, 0.275 mol) portion wise with maintaining inner temperature at 15-20 0C followed by the addition of CuSO4.5H2O (42.75 g, 0.171 mol) at 20 0C. Then reaction mixture was heated to 60-65 0C for 1 h under stirring and cooled to room temperature. To this reaction mixture was added DMF (200 ml) followed by drop wise addition of benzyl chloride (38.12 ml, 0.33 mol) at room temperature. Then reaction mixture was heated to 55 0C for 2 h under stirring. Grey coloured solid copper complex of O-benzyl- L-tyrosine was precipitated out. The reaction mixture was allowed come to at room temperature, and water (500 ml) was added to get free grey coloured solid. This solid was filtered washed with water till the filtrate became colourless. This wet cake of O-benzyl-L- tyrosine copper complex was stirred with methanol (800 ml) at reflux temperature for 1 h, filtered, washed with methanol and dried in an oven at 65 0C. To this copper complex was added 800 ml of water followed by the addition of dilute HCl (50 ml in 250 ml of water) to get pR 2-3 under stirring at room temperature. The solid so obtained was filtered, washed with 10% ammonia solution (150 ml), and dried in vacuum oven at 65 0C to yield the title compound (46.0 g, 62%). mp: 259-260 0C MS: m/z 294 (M+23)

References:

LUPIN LIMITED WO2008/10238, 2008, A2 Location in patent:Page/Page column 83-84

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