Trimethyl borate → 2,8-Diphenyldibenzothiophen-4-boronic acid

HRID 1748937Notes

Reaction equation

[C:1]1([C:7]2[CH:25]=[CH:24][C:10]3[S:11][C:12]4[CH:17]=[CH:16][C:15]([C:18]5[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=5)=[CH:14][C:13]=4[C:9]=3[CH:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C([Li])CCC.C[O:32][B:33](OC)[O:34]C>O1CCCC1>[C:18]1([C:15]2[CH:16]=[C:17]([B:33]([OH:34])[OH:32])[C:12]3[S:11][C:10]4[CH:24]=[CH:25][C:7]([C:1]5[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=5)=[CH:8][C:9]=4[C:13]=3[CH:14]=2)[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=1

Participants

Conditions

Temperature: -78 °C

Procedure

2,8-diphenyldibenzo[b,d]thiophene (6.0) was dissolved in anhydrous tetrahydrofuran (80 mL) under nitrogen atmosphere and the solution was then cooled to −78° C. 20.0 mL of n-butyl lithium (1.6 M solution) was added dropwise into the reaction mixture and continuously stirred to equilibrate to room temperature. The reaction mixture was then cool to −60° C. and trimethyborate (5.67 mL) was added and the reaction was allowed to stir overnight. The reaction was then quenched with 20% aqueous hydrochloric acid, and extracted the organic layer with ethyl acetate; ethyl acetate layer was then washed thoroughly with water and dried over anhydrous sodium sulfate, and was evaporated to dryness to yield 4.5 g of 2,8-diphenyldibenzo[b,d]thiophene-4-boronic acid.

Workup

customto equilibrate to room temperature
temperatureThe reaction mixture was then cool to −60° C.
stirringto stir overnight
customThe reaction was then quenched with 20% aqueous hydrochloric acid
extractionextracted the organic layer with ethyl acetate
washethyl acetate layer was then washed thoroughly with water
dry with materialdried over anhydrous sodium sulfate
customwas evaporated to dryness

Sources & evidence

ORD record: ord-f70a1012d1bf41b892ee1042b96380c6
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09153787B2

Reaction notes

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