Ethyl chloroformate → HCID 14024256, compound

HRID 1650328Notes

Reaction equation

HRID 1650328 reaction equation
[O:1]([CH2:9][CH2:10][N:11]=[N:12][NH:13][CH3:14])[Si:2]([C:5]([CH3:8])([CH3:7])[CH3:6])([CH3:4])[CH3:3].[H-].[K+].C1CC2OCCOCCOC3C(OCCOCCOC2CC1)CCCC3.[H][H].Cl[C:46]([O:48][CH2:49][CH3:50])=[O:47].[OH-].[NH4+].[Cl-].[NH4+]>CCOCC>[O:1]([CH2:9][CH2:10][N:11]=[N:12][N:13]([C:46]([O:48][CH2:49][CH3:50])=[O:47])[CH3:14])[Si:2]([C:5]([CH3:8])([CH3:7])[CH3:6])([CH3:3])[CH3:4]

Participants

9

Reactant 7

HCID 10928Ethyl chloroformateHCID 14923Ammonium HydroxideHCID 25517Ammonium ChlorideHCID 82127Potassium hydrideHCID 85955Dicyclohexano-18-crown-6HCID 178418361HCID 178418361, compoundHCID 178486253HCID 178486253, compound

Product 1

HCID 14024256HCID 14024256, compoundYield 58.6%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent3×

Conditions

Temperature
-30 °C

Procedure

A solution of 1-(2-(tert-butyldimethylsiloxy)ethyl)-3-methyltriazene, 3, (24.0 g, 0.11 mol) in anhydrous ether (70 mL) was added dropwise over 1.5 h to a stirred suspension of potassium hydride (- 6 g, 0.15 mol) in anhydrous ether containing 50 mg (1.3×10-4 mol) of dicyclohexano-18-crown-6 ether at 25° C. under nitrogen. Stirring was continued for 30 min until hydrogen evolution had ceased. The reaction mixture was cooled to -30° C. and then ethyl chloroformate (13.1 g, 0.12 mol) in anhydrous ether (70 mL) was added dropwise with stirring over 2 h. the reaction was stirred and allowed to warm gradually to 0° C. over 30 minutes, at which time hydrolysis was accomplished by the careful addition of 250 mL of 10% ammonium hydroxide solution containing 10% (w/v) ammonium chloride. The ether layer was separated and the aqueous layer was reextracted with pentane (100 mL). The ether and pentane layers were combined and dried twice over anhydrous sodium sulfate, and concentrated on a rotary evaporator at 25° C. Distillation of 1/10 of the crude product at reduced pressure using a short path distillation head gave 1.68 g (6.45×10-2 mol, 58.6% yield based on the fraction of total product distilled) of 1-(2-(tert-butyldimethylsiloxy)ethyl)-3-carboethoxy-3-methyltriazene, 4a: bp 90°-95° C. (0.07 mm); IR(Cl4) 2960, 2940, 2860, 1725, 1160, 840 cm -1 ; 1H NMR (CDCl3, Me4Si) δ 0.04 (6H,s), 0,87 (9H,s), 1.37 (3H,t,J=7 Hz), 3.24 (3H,s), 3.92 (2H,m), 4.94 (2H,m), 4.38 (2H,q,J=7 Hz); proton decoupled 13C NMR (CDCl3, Me4Si) δ-5.36, 14.45, 18.21, 25.89, 29.41, 61.20, 62.87, 63.87, 154.5. The crude product was determined to be sufficiently pure to be used directly in the following reaction.

Workup

  1. stirringwith stirring over 2 h. the reaction
  2. stirringwas stirred
  3. temperatureto warm gradually to 0° C. over 30 minutes, at which time hydrolysis
  4. customThe ether layer was separated
  5. dry with materialdried twice over anhydrous sodium sulfate
  6. concentrationconcentrated on a rotary evaporator at 25° C
  7. distillationDistillation of 1/10 of the crude product at reduced pressure
  8. distillationa short path distillation head
  9. customgave 1.68 g (6.45×10-2 mol, 58.6% yield
  10. distillationdistilled) of 1-(2-(tert-butyldimethylsiloxy)ethyl)-3-carboethoxy-3-methyltriazene, 4a
  11. customto be used directly in the following reaction

Sources & evidence

ORD record
ord-88b3429cec4d493abf14b8643b880d31
Source dataset
uspto-grants-1990_05
Patent number
US04923970

Reaction notes

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