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ChemicalBook CAS DataBase List N-Boc-N-methyl glycine methyl ester
42492-57-9

N-Boc-N-methyl glycine methyl ester synthesis

9synthesis methods
-

Yield: 90%

Reaction Conditions:

with triethylamine in dichloromethane at 0 - 20; for 48 h;Inert atmosphere;

Steps:

N-tert-Butoxycarbonyl-sarcosine methyl ester 2
To a suspension of sarcosine (35.64 g, 0.40 mol) in 350 mL MeOH was added thionyl chloride (29.02 mL, 0.40 mol) dropwise at 0 °C. After complete addition the cooling bath was removed and the reaction mixture was stirred for 30 min at r.t. and refluxed for further 6 h. The resulting solution was concentrated in vacuum and the residue was dried in high vacuum over night at r.t. to afford sarcosine methyl ester.HCl as a white powder which was used in the next step without further purification; yield: 56.14 g (quant.); mp. 102 °C. 1H-NMR (300 MHz, CDCl3): δ = 9.76 (s, 2 H, NH2), 3.88 (t, J = 5.6 Hz, 2 H, H-2), 3.82 (s, 3 H, H-4)), 2.83 (t, J = 5.2 Hz, 3 H, H-3). 13C-NMR(75 MHz, CDCl3): δ = 166.7 (C-1), 53.3 (C-2), 48.9 (C-3), 33.4 (C-4).1 To a suspension of sarcosine methylester.HCl (59.80 g, 0.43 mol) and (Boc)2O (138.01 mL, 0.65 mol) in 1.0 L CH2Cl2 TEA (119.09 mL, 0.86 mol) was added dropwise at 0 °C. After complete addition the cooling bath was removed and the reaction mixture was stirred for two days at r.t. Aq. HCl (1 M) was added until the aqueous layer showed pH = 6. The resulting two layers were separated and the organic layer was washed with dist. H2O, dried (Na2SO4), concentrated in vacuum and volatile impurities were removed in high vacuum over night at r.t. to afford a clear oil; yield: 78.65 g (90 %)

References:

Przybyla, Daniel;Nubbemeyer, Udo [Synthesis,2017,vol. 49,# 4,art. no. SS-2016-Z0507-OP,p. 770 - 774] Location in patent:supporting information

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