Hydrochloric Acid → 2-Formyl-3-thiopheneboronic acid

HRID 1611599Notes

Reaction equation

HRID 1611599 reaction equation
C([Li])CCC.Br[C:7]1[CH:11]=[CH:10][S:9][C:8]=1[CH:12]1[O:16]CCO1.[B:17]([O-])([O-:23])[O:18]CCCC.Cl>CCCCCC.CCOCC>[CH:12]([C:8]1[S:9][CH:10]=[CH:11][C:7]=1[B:17]([OH:23])[OH:18])=[O:16]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 122202112-(3-Bromothiophen-2-yl)-1,3-dioxolaneHCID 86592051n-ButylborateHCID 178418339Butyllithium

Product 1

HCID 27734262-Formyl-3-thiopheneboronic acidYield 50.2%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent2×HCID 8058HexaneSolvent

Procedure

A 1.1 N solution of n-butyllithium in hexane (28 ml). was added dropwise (10 mins) to a solution of 2-(3-bromo-2-thienyl)-1,3-dioxalane (3) (6.6 g, 28.1 mmol) in anhydrous ether (30 ml) at −70° C. After stirring for 10 mins, butyl borate (9.1 ml, 33.7 mmol) in anhydrous ether (20 ml) was added in a single portion. The reaction mixture was stirred for 4 hrs at −70° C. and then left to return to room temperature. 1 N hydrochloric acid (20 ml) was added, and the mixture was left for 1 hr with stirring. The aqueous phase was extracted with ether and the combined ether phases were washed with a solution of sodium bicarbonate, dried (Na2SO4), and evaporated under reduced pressure to give the intermediate (4) (2.2 g, 14.1 mmol, 50% yield) as a brown solid.

Workup

  1. stirringThe reaction mixture was stirred for 4 hrs at −70° C.
  2. waitleft
  3. customto return to room temperature
  4. waitthe mixture was left for 1 hr
  5. stirringwith stirring
  6. extractionThe aqueous phase was extracted with ether
  7. washthe combined ether phases were washed with a solution of sodium bicarbonate
  8. dry with materialdried (Na2SO4)
  9. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-9978e0d85b124f1ba62f54fcfba7ee84
Source dataset
uspto-grants-2006_01
Patent number
US06989388B2

Reaction notes

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