Ethyl chloroformate → HCID 54275443, compound

HRID 1597458Notes

Reaction equation

HRID 1597458 reaction equation
[C:1]([N:8]1[CH2:15][S:14][CH2:13][C@H:9]1[C:10](O)=[O:11])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].CCN(C(C)C)C(C)C.ClC(OCC)=O.[BH4-].[Na+]>C1COCC1.O>[C:4]([O:3][C:1]([N:8]1[C@H:9]([CH2:10][OH:11])[CH2:13][S:14][CH2:15]1)=[O:2])([CH3:7])([CH3:6])[CH3:5]

Participants

7

Reactant 4

HCID 10928Ethyl chloroformateHCID 81531DiisopropylethylamineHCID 688405(4R)-3-[(tert-butoxy)carbonyl]-1,3-thiazolidine-4-carboxylic acidHCID 4311764Sodium borohydride

Product 1

HCID 54275443HCID 54275443, compoundYield 53.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 4.66 g (20 mmol) of N-Boc-thioproline and 3.84 mL (22 mmol) DIEA dissolved in 10 mL THF was cooled to 0_C and treated with 2.1 mL (22 mmol) of ethyl chloroformate. After 30 min at RT the white precipitate is filtered off, the solution cooled to 0° C. and a solution of 8.32 g (220 mmol) sodium borohydride in 30 mL H2O is added dropwise. The reaction was stirred for 24 h, then cooled to 0° C. and quenched by dropwise addition of acetic acid. The product was then extracted with EtOAc, the combined organics were washed successively with sodium bicarbonate and citric acid, dried with magnesium sulfate, filtered and solvents removed in vacuo to provide 2.33 g of the title compound: MS (ES+) m/e 242 (M+23), 120 (M-Boc+1).

Workup

  1. temperaturewas cooled to 0_C
  2. filtrationAfter 30 min at RT the white precipitate is filtered off
  3. temperaturecooled to 0° C.
  4. customquenched by dropwise addition of acetic acid
  5. extractionThe product was then extracted with EtOAc
  6. washthe combined organics were washed successively with sodium bicarbonate and citric acid
  7. dry with materialdried with magnesium sulfate
  8. filtrationfiltered
  9. customsolvents removed in vacuo

Sources & evidence

ORD record
ord-8a263c1510fd4c8d8901635209071c4d
Source dataset
uspto-grants-2001_09
Patent number
US06294580B1

Reaction notes

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