Hydrochloric Acid → 1,2,3,4-Tetrahydro-1,4-methanonaphthalene-5-boronic Acid

HRID 1190773Notes

Reaction equation

C([Li])CCC.Br[C:7]1[CH:16]=[CH:15][CH:14]=[C:13]2[C:8]=1[CH:9]1[CH2:17][CH:12]2[CH2:11][CH2:10]1.[B:18](OC)([O:21]C)[O:19]C.Cl>C1COCC1.C(OC)(C)(C)C>[CH:12]12[CH2:17][CH:9]([C:8]3[C:7]([B:18]([OH:21])[OH:19])=[CH:16][CH:15]=[CH:14][C:13]=31)[CH2:10][CH2:11]2

Participants

Conditions

Temperature: -78 °C

Procedure

100 ml (250 mmol) of n-butyllithium (2.5M in hexane) are added dropwise to a solution, cooled to −78° C., of 44.6 g (200 mmol) of 5-bromo-1,2,3,4-tetrahydro-1,4-methanonaphthalene in 500 ml of THF. The reaction mixture is stirred at −78° C. for 1 h, and a mixture of 33.5 ml (300 mmol) of trimethyl borate in 50 ml of THF is then added rapidly. After warming to −10° C., the mixture is hydrolysed using 10 ml of 2.5M hydrochloric acid, and 500 ml of methyl tert-butyl ether are then added. The organic phase is separated off, washed with water, dried over sodium sulfate and evaporated to dryness. The residue is taken up in 200 ml of n-heptane, and the colourless solid is filtered off with suction, washed with n-heptane and dried under reduced pressure. Yield: 24.1 g (128 mmol), 64.1% of theory; purity: 98% according to 1H-NMR.

Workup

additionis then added rapidly
temperatureAfter warming to −10° C.
additionare then added
customThe organic phase is separated off
washwashed with water
dry with materialdried over sodium sulfate
customevaporated to dryness
filtrationthe colourless solid is filtered off with suction
washwashed with n-heptane
customdried under reduced pressure

Sources & evidence

ORD record: ord-7270a87a137744ed9fe879277131339f
Source dataset: uspto-grants-2014_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08679645B2

Reaction notes

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