Tributyltin Chloride → 1,5,5-trimethyl-3-tributylstannanyl-4,5,6,7-tetrahydro-1H-indazole

HRID 245816Notes

Reaction equation

I[C:2]1[C:10]2[CH2:9][C:8]([CH3:12])([CH3:11])[CH2:7][CH2:6][C:5]=2[N:4]([CH3:13])[N:3]=1.C([Mg]Cl)(C)C.[CH2:19]([Sn:23]([CH2:29][CH2:30][CH2:31][CH3:32])([CH2:25][CH2:26][CH2:27][CH3:28])Cl)[CH2:20][CH2:21][CH3:22]>C1COCC1>[CH3:13][N:4]1[C:5]2[CH2:6][CH2:7][C:8]([CH3:12])([CH3:11])[CH2:9][C:10]=2[C:2]([Sn:23]([CH2:25][CH2:26][CH2:27][CH3:28])([CH2:29][CH2:30][CH2:31][CH3:32])[CH2:19][CH2:20][CH2:21][CH3:22])=[N:3]1

Participants

Conditions

Temperature: -16 °C

Procedure

In a round-bottomed flask, 3-iodo-1,5,5-trimethyl-4,5,6,7-tetrahydro-1H-indazole (140 mg, 0.48 mmol) was dissolved in THF (3 ml). The colorless solution was cooled to −16° C. (NaCl/ice bath) and isopropylmagnesium chloride (2.0M in THF, 0.27 ml, 0.54 mmol) was added dropwise. The reaction mixture was stirred at −16° C. for 20 min then tributylchlorostannane (0.15 ml, 0.55 mmol) was slowly added. The reaction mixture was allowed to warm to room temperature over 1.5 h then quenched with saturated NH4Cl, diluted with water and extracted with EtOAc (2×). The combined organic layers were washed with water and brine then dried over sodium sulfate, filtered and concentrated to afford 1,5,5-trimethyl-3-tributylstannanyl-4,5,6,7-tetrahydro-1H-indazole as a colorless oil which was used without further purification.

Workup

additionwas added dropwise
temperatureto warm to room temperature over 1.5 h
customthen quenched with saturated NH4Cl
additiondiluted with water
extractionextracted with EtOAc (2×)
washThe combined organic layers were washed with water and brine
dry with materialthen dried over sodium sulfate
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-c8b92a1a2a0d4e73b1776214bd45c457
Source dataset: uspto-grants-2014_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08658646B2

Reaction notes

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