Reaction #1246

Reaction equation

pyridine

TBDMSCl

histidinol

NaH

histidinol dihydrochloride

→

NH3 CH2Cl2

14

histidinol

Solvents

hexane

DMF

Conditions

Workup

1. 1
   Otherresulting in moderate gas evolution
2. 2
   workup.STIRRINGThe solution was stirred for 1.5 h
3. 3
   Concentrationconcentrated in vacuo and flash
4. 4
   Otherchromatographed on silica with 15% CH3OH

Procedure

TBDMS protected histidinol 14--To a stirred solution of 205 mg (5.1 mmol) of NaH washed 3× with hexane, under argon, in 3.0 mL DMF was added in portions 500 mg (2.3 mmol) of histidinol dihydrochloride, resulting in moderate gas evolution. The solution was stirred for 1.5 h, then 1.8 mL (23 mmol) of anhydrous pyridine and 693.0 mg (4.6 mmol) of TBDMSCl was added. The solution was stirred for 1.5 h, concentrated in vacuo and flash chromatographed on silica with 15% CH3OH.NH3 /CH2Cl2 to yield 14.

Source