- Access to "friedel-Crafts-Restricted" tert -alkyl aromatics by activation/methylation of tertiary benzylic alcohols
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Herein we describe a two-step protocol to prepare m-tert-alkylbenzenes. The appropriate tertiary benzylic alcohols are activated with SOCl2 or concentrated HCl and then treated with trimethylaluminum, affording the desired products in 68-97% yields (22 examples). This reaction sequence is successful in the presence of a variety of functional groups, including acid-sensitive and Lewis-basic groups. In addition to t-Bu groups, 1,1-dimethylpropyl and 1-ethyl-1-methylpropyl groups can also be installed using this method.
- Hartsel, Joshua A.,Craft, Derek T.,Chen, Qiao-Hong,Ma, Ming,Carlier, Paul R.
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experimental part
p. 3127 - 3133
(2012/05/20)
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- Synthesis and pharmacological evaluation of 1-Alkyl-N-[(1R)-1-(4- fluorophenyl)-2-methylpropyl]piperidine-4-carboxamide derivatives as novel antihypertensive agents
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We synthesized and evaluated inhibitory activity against T-type Ca 2+ channels for a series of 1-alkyl-N- [(1R)-1-(4-fluorophenyl)-2- methylpropyl]piperidine-4-carboxamide derivatives. Structure-activity relationship studies have revealed that the isopropyl substituent at the benzylic position plays an important role in exerting potent inhibitory activity, and the absolute configuration of the benzylic position was found to be opposite that of mibefradil, which was first launched as a new class of T-type Ca2+ channel blocker. Oral administration of N- [(1R)-1-(4-fluorophenyl)-2-methylpropyl]-1-[2-(3-methoxyphenyl)ethyl] piperidine-4-carboxamide (17f) lowered blood pressure in spontaneously hypertensive rats without inducing reflex tachycardia, an adverse effect often caused by traditional L-type Ca2+ channel blockers.
- Watanuki, Susumu,Matsuura, Keisuke,Tomura, Yuichi,Okada, Minoru,Okazaki, Toshio,Ohta, Mitsuaki,Tsukamoto, Shin-Ichi
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experimental part
p. 1376 - 1385
(2012/01/05)
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- Antiestrogens. Synthesis and Evaluation of Mammary Tumor Inhibiting Activity of 1,1,2,2-Tetraalkyl-1,2-diphenylethanes
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Among the newly synthesized 1,1,2,2-tetraalkyl-1,2-diphenylethanes, 1,1,2,2-tetramethyl-1,2-bis(4'-hydroxyphenyl)ethane (23) and 1,1,2,2-tetramethyl-1,2-bis(3'-hydroxyphenyl)ethane (26) were the most active compounds regarding estradiol receptor affinity, exhibiting Ka values of 0.73*108 and 0.67*108 M-1, respectively.In vivo, 23 and 26 showed only very small uterotrophic activity in the mouse.They strongly inhibited (73percent) the estrone-stimulated mouse uterine growth.Tested on the 9,10-dimethyl-1,2-benzanthracene induced hormone-dependent mammary adenocarcinoma of the Sprague-Dawley rat, compounds 23 and 26 exhibited a dose-dependent inhibition of the tumor growth, having a strong effect at a dose of 20 (mg/kg)/day (compound 23).
- Hartmann, Rolf W.,Kranzfelder, Gerhard,Angerer, Erwin, v.,Schoenenberger, Helmut
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p. 841 - 848
(2007/10/02)
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