Preparation and use of LiEt3Bt and LiAlT4 at maximum specific activity

Abstract

Carrier-free LiEt3BT and LiAIT4 have been generated and used to reduce methyl 2-naphthoate to 2-( hydroxymethy1)naphthalene containing two tritium atoms per molecule.

Tritiation of the cannabinoid receptor antagonist SR144528 involving lithium aluminum tritide reduction; assessment of the kinetic isotope effect by 3H‐NMR

“…To LiAlT 4 (prepared from 0.15 mmol carrier free tritium gas, 0.24 mmol n-BuLi, 0.24 mol TMEDA, and 0.06 mmol ALBr 3 as reported 10 ), an excess of methyl 4-methylbenzoate 5 in dry benzene (36 mg/ml) (0.5 ml, 0.12 mmol) was added and the reaction mixture was stirred for 1 h. Anhydrous ether (0.5 ml) was added affording a homogeneous solution and stirred for 15 min. The reaction was quenched with 0.1 ml water, 0.1 ml 15% NaOH, and 0.1 ml water and stored in 2 ml ethanol at À708C overnight.…”

“…10 Addition of excess methyl 4-methylbenzoate 5 to the lithium aluminum tritide afforded tritiated 4-methylbenzyl alcohol 6. Bromination with triphenylphosphine and carbon tetrbromide 11,12 provided the tritiated 4-methylbenzyl bromide 7 which was chromatographed and used to benzylate 4 as described above.…”

Synthesis of [3H] vardenafil, Levitra®, using a new labeling technique

“…For that very reason a special amide precursor 3 was synthesized in order to reduce the amide to the tertiary amine with lithium aluminum tritide, which was freshly prepared starting from butyl lithium. 2 Hydrogenation of butyl lithium with tritium in the presence tetramethylethylenediamine (TMEDA) yielded lithium tritide, which was subsequently reacted with aluminum tribromide, yielding lithium aluminum tritide.…”

Synthesis of a new selective borotritide : [3H]lithium9‐boratabicyclo[3.3.1]nonane. Some applications to the preparation of secondary and primary [3H] alcohols

“…In recent years, the emergence of new tritium labelling tools(l,2) evolved from the easy access to lithium tritide (2,3). Especially, P.G.…”