- Combinatorial synthesis of PEG oligomer libraries
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A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
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Page/Page column 9
(2010/02/15)
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- Lipophilic diesters of chelating agents
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The invention discloses stable diesters of chelating agents of divalent metal ions, processes for their preparation and pharmaceutical compositions thereof. Most preferred compounds according to the present invention are stable lipophilic diesters comprising a covalent conjugate of a BAPTA and a pharmaceutically acceptable alcohol. The diesters are useful in a method for treating a condition or disease related to an excess of divalent metal ions, and in particular for the treatment of a condition or disease related to elevated levels of intracellular calcium ions, such as in brain or cardiac ischemia, stroke, epilepsy, Alzheimer's disease or cardiac arrhythmia and in open heart surgery.
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- Topical mosquito repellents VII: Alkyl triethylene glycol monoethers
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Normal and branched chain aliphatic monoethers of triethylene glycol are effective topical mosquito repellents. In terms of duration of protection, they are generally superior to the corresponding diethylene glycol analogs, and some are superior to diethyltoluamide. The n heptyl monoether of triethylene glycol affords double the protection time of diethyltoluamide under controlled laboratory conditions, and appears to be a useful new mosquito repellent.
- Johnson,DeGraw,Engstrom,Skinner,Brown,Skidmore,Maibach
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p. 693 - 695
(2007/10/05)
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