Tributyltin Chloride → 1-methyl-3-(tributylstannyl)-4,5,6,7-tetrahydro-1H-indazole

HRID 246413Notes

Reaction equation

I[C:2]1[C:10]2[CH2:9][CH2:8][CH2:7][CH2:6][C:5]=2[N:4]([CH3:11])[N:3]=1.C([Mg]Cl)(C)C.[CH2:17]([Sn:21]([CH2:27][CH2:28][CH2:29][CH3:30])([CH2:23][CH2:24][CH2:25][CH3:26])Cl)[CH2:18][CH2:19][CH3:20]>C1COCC1>[CH3:11][N:4]1[C:5]2[CH2:6][CH2:7][CH2:8][CH2:9][C:10]=2[C:2]([Sn:21]([CH2:23][CH2:24][CH2:25][CH3:26])([CH2:27][CH2:28][CH2:29][CH3:30])[CH2:17][CH2:18][CH2:19][CH3:20])=[N:3]1

Participants

Conditions

Temperature: -16 °C

Procedure

In a 25 mL round-bottomed flask, 3-iodo-1-methyl-4,5,6,7-tetrahydro-1H-indazole (62 mg, 237 μmol) was dissolved in THF (3 mL). The colorless solution was cooled to −16° C. (NaCl/ice bath) and isopropylmagnesium chloride 2 M in THF (132 μL, 265 μmol) was added dropwise at −16° C. The reaction mixture was stirred at −16° C. for 20 min. Then, tributylchlorostannane (88.6 mg, 73.8 μL, 272 μmol) was added slowly. The reaction mixture was warmed to 25° C. and stirred for 1.5 h. The reaction mixture was quenched with saturated ammonium chloride solution, extracted with dichloromethane (3×30 mL), organics dried over MgSO4 and concentrated to an off-white waxy solid. The residue was dried under high vacuum yielding 1-methyl-3-(tributylstannyl)-4,5,6,7-tetrahydro-1H-indazole assumed quantitative and taken into next step without further treatment.

Workup

additionwas added dropwise at −16° C
temperatureThe reaction mixture was warmed to 25° C.
stirringstirred for 1.5 h
customThe reaction mixture was quenched with saturated ammonium chloride solution
extractionextracted with dichloromethane (3×30 mL)
dry with materialorganics dried over MgSO4
concentrationconcentrated to an off-white waxy solid
customThe residue was dried under high vacuum

Sources & evidence

ORD record: ord-9c95be95defe4c50b4fc0b81e48d6d6e
Source dataset: uspto-grants-2014_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08658646B2

Reaction notes

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