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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