136809-03-5Relevant academic research and scientific papers
Preparations, X-ray crystal structure determinations, and base strength measurements of substituted tritylamines
Canle, Moises L.,Clegg, William,Demirtas, Ibrahim,Elsegood, Mark R.J.,Maskill, Howard
, p. 85 - 92 (2007/10/03)
A range of tritylamines TrNRR′, and 4-methoxy-, 4,4′-dimethoxy-, and 4,4′,4″-trimethoxy-substituted analogues, have been prepared from (substituted) trityl chloride, bromide, or tetrafluoroborate with ammonia or with amines HNRR′ where R and R′ are hydrog
4,4′-Dimethoxytrityl and 4,4′,4″-trimethoxytrityl as protecting groups for amino functions; selectivity for primary amino groups and application in 15N-labelling
Henderson, Alistair P.,Riseborough, Jane,Bleasdale, Christine,Clegg, William,Elsegood, Mark R. J.,Golding, Bernard T.
, p. 3407 - 3413 (2007/10/03)
4,4′-Dimethoxytrityl tetrafluoroborate (DMT+ BF4-) and 4,4′,4″-trimethoxytrityl tetrafluoroborate (TMT+ BF4-) are useful reagents for protecting primary and some secondary amines. Protected amines are obtained either by reaction of DMT+ BF4- or TMT+ BF4- with the amine or by alkylating DMT- or TMT-amine (available from DMT+ BF4- and TMT+ BF4- by treatment with ammonia). Alkylation of DMT- or TMT-amine stops after monoalkylation. Deprotection of the alkylated DMT- and TMT-amine is achieved by treatment with an acid of appropriate molarity (e.g. 0.1 M HCl in 1:1 tetrahydrofuran-water for TMT-amines). The value of the methodology described is illustrated by a synthesis of (15NH2) adenosine. X-Ray molecular structures of one DMT and two TMT derivatives are reported.
Molar Absorptivity and pKR+ of the 4,4'-Dimethoxytrityl Carbenium Ion in Methanolic Water, and its Equilibrium with Chloride Ion
Lee, Won Heui,Maskill, H.
, p. 1463 - 1466 (2007/10/02)
The 4,4'-dimethoxytrityl carbenium ion has been generated in 80:20 (v/v) water-methanol containing perchloric acid in a rapid reaction from 4,4'-dimethoxytrityl alcohol and in a slower reaction from 4,4'-dimethoxytritylamine.The pK (-0.95; K=8.98) and molar absorptivity (ε=297 000) of the cation have been measured directly under equilibrium conditions in this highly aqueous medium at ionic strength = 1.0 mol dm-3 by a convenient spectrophotometric method at 25 deg C.In addition, the pK has been measured at other temperatures, which allows the determination of the standard enthalpy (ΔH = -11.4 kJ mol-1) and entropy (ΔS = -20 J K-1 mol-1) of the reaction of the cation with the solvent, and at other ionic strengths.The equilibrium constant for the formation of 4,4'-dimethoxytrityl chloride from the cation and chloride has also been measured in the same medium (KRCl = 8.20 at 25.0 deg C, ionic strength = 1.0 mol dm-3) by generating the cation from the alcohol and perchloric acid in the presence of 0.10 mol dm-3 sodium chloride.
