Diisopropylamine → Furo[3,2-c]pyridine-2-sulfonamide

HRID 1382985Notes

Reaction equation

HRID 1382985 reaction equation
C([NH:4]C(C)C)(C)C.C([Li])CCC.CCCCCC.[O:19]1[C:27]2[CH:26]=[CH:25][N:24]=[CH:23][C:22]=2[CH:21]=[CH:20]1.O.O.O.C([O-])(=O)C.[Na+].N[O:37][S:38]([OH:41])(=O)=O>O1CCCC1>[S:38]([C:20]1[O:19][C:27]2[CH:26]=[CH:25][N:24]=[CH:23][C:22]=2[CH:21]=1)(=[O:41])(=[O:37])[NH2:4]

Participants

8

Reactant 6

HCID 7912DiisopropylamineHCID 8058HexaneHCID 76284hydroxylamine-O-sulfonic acidHCID 12234604Furo[3,2-c]pyridineHCID 23665404Sodium Acetate TrihydrateHCID 178418339Butyllithium

Product 1

HCID 14372124Furo[3,2-c]pyridine-2-sulfonamideYield 41%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-70 °C

Procedure

To a solution of distilled diisopropylamine (16.2 ml, 0.116 mol) in distilled tetrahydrofuran (115 ml), cooled at -10° C., under a nitrogen atmosphere, was added 1.56M butyl lithium in hexane (75.3 ml, 0.117 mol). After 15 minutes, the solution was cooled to -70° C. and there was added dropwise a solution of furo[3,2-c]pyridine (11.74 g, 0.0987 mol) in tetrahydrofuran (70 ml). With vigorous stirring the gummy precipitate formed a salmon-colored powder. After one hour, sulfur dioxide gas was bubbled over the surface with gradual warming to room temperature. The suspension was diluted with diethyl ether (200 ml) and the precipitate was collected by filtration. This crude lithium sulfinate intermediate (29.1 g) was dissolved in water (200 ml) and sodium acetate trihydrate (61 g, 0.45 mol) and hydroxylamine-O-sulfonic acid (18 g, 0.16 mol) were added. The solution was stirred for 18 hours as the product slowly precipitated. The precipitated product was collected by filtration and redissolved in ethyl acetate/methanol, dried over anhydrous sodium sulfate, filtered through a pad of charcoal and evaporated to give white crystalline product (8.0 g, 41% yield). This material was recrystallized from ethyl acetate/methanol to give 6.7 g, m.p. 216°-218° C.

Workup

  1. customformed a salmon-colored powder
  2. waitAfter one hour
  3. customsulfur dioxide gas was bubbled over the surface
  4. temperaturewith gradual warming to room temperature
  5. additionThe suspension was diluted with diethyl ether (200 ml)
  6. filtrationthe precipitate was collected by filtration
  7. dissolutionThis crude lithium sulfinate intermediate (29.1 g) was dissolved in water (200 ml)
  8. stirringThe solution was stirred for 18 hours as the product
  9. customslowly precipitated
  10. filtrationThe precipitated product was collected by filtration
  11. dissolutionredissolved in ethyl acetate/methanol
  12. dry with materialdried over anhydrous sodium sulfate
  13. filtrationfiltered through a pad of charcoal
  14. customevaporated

Sources & evidence

ORD record
ord-8d180260af504cbaa1db032f6826a682
Source dataset
uspto-grants-1989_02
Patent number
US04808595

Reaction notes

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