Potassium Phosphate, Tribasic → 3-(2-methoxyphenyl)methyl-N-BOC-histidine methyl ester

HRID 1194150Notes

Reaction equation

CS(OS(C)(=O)=O)(=O)=O.[CH3:10][O:11][C:12]1[CH:19]=[CH:18][CH:17]=[CH:16][C:13]=1[CH2:14]O.C(N(C(C)C)CC)(C)C.[CH3:29][O:30][C:31](=[O:54])[C@H:32]([CH2:41][C:42]1[N:46]=[CH:45][N:44](C(OC(C)(C)C)=O)[CH:43]=1)[NH:33][C:34]([O:36][C:37]([CH3:40])([CH3:39])[CH3:38])=[O:35].P([O-])([O-])([O-])=O.[K+].[K+].[K+]>ClCCl>[CH3:29][O:30][C:31](=[O:54])[C@H:32]([CH2:41][C:42]1[N:46]([CH2:14][C:13]2[CH:16]=[CH:17][CH:18]=[CH:19][C:12]=2[O:11][CH3:10])[CH:45]=[N:44][CH:43]=1)[NH:33][C:34]([O:36][C:37]([CH3:40])([CH3:38])[CH3:39])=[O:35]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of 8 g methanesulfonic anhydride in 45 mL dichloromethane is chilled to -50° C. and treated dropwise with a solution of 6.2 mL 2-methoxybenzyl alcohol, 8.0 mL diisopropylethylamine and 45 mL dichloromethane. The resulting solution is warmed to 0° C. over 30 min and treated dropwise with 15.0 g N,1-bis-BOC-histidine methyl ester dissolved in 45 mL dichloromethane. The mixture is then heated at reflux 24 hr, poured into 400 mL 0.25M, pH=7 potassium phosphate buffer and the organic layer is separated, dried and evaporated. Chromatography on silica gel, eluting with chloroform-methanol (99:1) gives 3-(2-methoxyphenyl)methyl-N-BOC-histidine methyl ester as a gum. NMR (CDCl3) 4.96 (s,2H,NCH2Ar).

Workup

temperatureThe mixture is then heated
temperatureat reflux 24 hr
customthe organic layer is separated
customdried
customevaporated
washChromatography on silica gel, eluting with chloroform-methanol (99:1)

Sources & evidence

ORD record: ord-90d12253e8ce4164badf3b1a59f4fb2b
Source dataset: uspto-grants-1989_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04812462

Reaction notes

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