Slappy
Where did you pull that one from? Got a reference??
Is it from here?
Organometallics, 4, 2117 (1985)
Good stuff
Patent US3534113
They perform a similar reaction here.
Patent US3663585
Example
Mixed 6ml Toluene, 5ml (1M)BuLi in n-hexane and 1ml (2M)TMEDA in n-hexane(I assume). Then allowed to stand under N2 for 3 days. Evap. to dryness yeilded 0.68g of yellow solid. They make some questionable judgements and say it yeilded 78%.
Here is some other interesting stuff
Patent US4006187
EXAMPLE I
Preparation of Benzyllithium
From 1-lithio-3-methylpentylbenzene
To 200 ml of sec-butyllithium in hexane (2.05 N) at -20.degree. C there is added 57.2 ml of TEA, followed by 47 ml (0.41 moles of styrene diluted with 30 ml of hexane. Then 43.5 ml of toluene (0.41 moles) is added and the resulting solution is placed in a constant temperature bath at 35.degree. C. Aliquots of the solution are removed periodically, treated with excess trimethylchlorosilane in diethyl ether, and analyzed by G.L.C. for 3-methylpentylbenzene, the amount of which hydrocarbon indicating the percentage of toluene metalated. The results are shown in the following tabulation:
______________________________________
Time (hrs) % Metalation
______________________________________
24 19.5
46 44
78 63
102 76
______________________________________
Metalation is essentially complete in 150 hrs. By contrast, n-butyllithium . TEA metalates toluene much more slowly, only about 10% metalation occurring in a period of 156 hrs at 35.degree. C.
Selective side chain lithiation of toluene and methylpyridines.
Screttas, Constantinos G.; Eastham, Jerome F.; Kamienski, Conrad W.
Chimia (1970), 24(3), 109-11.
Abstract
Benzyllithium (I) was prepd. free of ring-metalated by-products using n- or sec-BuLi and THF. 2- (II) and 4-Pyridylmethyllithium (III) were prepd. with THF and 2-thienyllithium. Solns. of II and III in 70:30 benzene-THF were stable 9 months under refrigeration. Reaction of picolyllithiums (a-, b-, g-) in THF with Ph2CO or PhCN gave 66-100% corresponding carbinols or phenacylpyridines. For example, THF (40 ml) was added to 18 ml (14.1 g) sec-BuLi in 180 ml toluene under N at -15 ± 1°. After addn. of 3/4 of the THF, the temp. rose to 0° and the mixt. solidified to a yellow cryst. mass (1:1 I-THF). The remaining THF and 10 ml extra dissolved the solid to give an orange-red soln., reaction time 3 hr, 98% yield PhCH2Li.
Lithiation of toluene in the presence of polycyclic aromatics and conjugated dienes.
Froehlich, Hans Otto; Scholz, Peter; Griehl, Volker; Stoye, Hartmut; Anton, Elisabeth.
Ger. (East) (1988), DD 256519 A1 19880511
Patent written in German.
Abstract
PhCH2Li was prepd. by addn. of a conjugated diene to a mixt. contg. 0.1-5 mol Li/L, 0.5-7.5 mol/L PhMe, 0.01-1 mol/L polycyclic arom., and 0.5-8 mol/L aliph. or cycloaliph. ether at (greater than or equal to)278 K followed by stirring at 283-340 K for 10-80 h. Thus, a mixt. of toluene 2, THF 2.7, Li 1.5, and naphthalene 0.1 mol in an autoclave at 268 K was treated with 7.5 mol butadiene at (greater than or equal to)278 K and the mixt. was stirred 48 h at 313 K to give 97% PhCH2Li.
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