Dibutyltin dichloride → 5-Bromo-3-(2,2-dimethyl-[1,3]dioxan-5-ylamino)-thiophene-2-carboxylic acid methyl ester

HRID 1694487Notes

Reaction equation

HRID 1694487 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([Br:11])=[CH:8][C:9]=1[NH2:10])=[O:4].[CH3:12][C:13]1([CH3:20])[O:18][CH2:17][C:16](=O)[CH2:15][O:14]1.C([Sn](Cl)(Cl)CCCC)CCC.C1([SiH3])C=CC=CC=1>C1COCC1.C(OCC)(=O)C>[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([Br:11])=[CH:8][C:9]=1[NH:10][CH:16]1[CH2:17][O:18][C:13]([CH3:20])([CH3:12])[O:14][CH2:15]1)=[O:4]

Participants

7

Reactant 4

HCID 12688Dibutyltin dichlorideHCID 12752PhenylsilaneHCID 27331412,2-Dimethyl-1,3-dioxan-5-oneHCID 20158931Methyl 3-amino-5-bromothiophene-2-carboxylate

Product 1

HCID 577954295-Bromo-3-(2,2-dimethyl-[1,3]dioxan-5-ylamino)-thiophene-2-carboxylic acid methyl esterYield 29.6%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

A suspension of 3-amino-5-bromo-thiophene-2-carboxylic acid methyl ester (0.5 g, 2.12 mmol) in dry THF (0.6 mL) was treated with 2,2-dimethyl-[1,3]dioxan-5-one (253 μl, 2.12 mmol), followed by dibutyltin dichloride (32 mg, 0.11 mmol). After 5 min phenyl silane (280 μl, 2.27 mmol) was added and the reaction was stirred at room temperature for 3 days. It was dissolved in ethyl acetate (100 mL), washed with NaHCO3 solution and brine. The organic layer was separated, dried over MgSO4, evaporated and left on vacuum pump overnight. The residue was triturated with hexane-ether (4:1) mixture (2×100 mL). The soluble portion was evaporated and purified by chromatography over silica gel (hexane:ethyl acetate-95:5) yielding pure 5-bromo-3-(2,2-dimethyl-[1,3]dioxan-5-ylamino)-thiophene-2-carboxylic acid methyl ester (220 mg, 29%).

Workup

  1. washwashed with NaHCO3 solution and brine
  2. customThe organic layer was separated
  3. dry with materialdried over MgSO4
  4. customevaporated
  5. waitleft on vacuum pump overnight
  6. customThe residue was triturated with hexane-ether (4:1) mixture (2×100 mL)
  7. customThe soluble portion was evaporated
  8. custompurified by chromatography over silica gel (hexane:ethyl acetate-95:5)

Sources & evidence

ORD record
ord-547256c628f147049250b8bcf4f85f82
Source dataset
uspto-grants-2012_04
Patent number
US08158675B2

Reaction notes

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