Hypnotics and Anticonvulsants. Ii. Halogenated Tertiary Acetylenic Carbinols

Abstract

In connection with a research program on tertiary acetylenic carbinols as central nervous system depressants,1 we were interested in determining the effect of halogen substitution on activity in this series. We therefore prepared and screened a number of halogenated acetylenic carbinols of different types.

Acetylene in Organic Synthesis: Recent Progress and New Uses

“…The Favorskii reaction is usually performed either by using a Grignard method, or in the presence of a base ( Scheme 69 ) [ 155 ]. The first procedure involves a preliminary reaction of acetylene with Grignard reagent or lithium, sodium, potassium in liquid ammonia or lithium-organic compounds [ 155 , 156 , 157 ]. The resulting acetylide reacts with the ketone giving a tertiary acetylenic alcohol.…”

“…The second procedure is equally widespread [ 155 , 158 ]. Both procedures afford acetylenic alcohols from aldehydes and ketones with arbitrarily chosen substituents in moderate to excellent yields [ 155 , 156 , 157 , 158 ].…”

“…Lithium acetylide was generated from acetylene and lithium metal in liquid ammonia. The procedure allows obtaining a range of ethynyl β -halogenvinyl carbinols [ 157 ].…”

Efficacy of ataractic drugs in clinical anaesthesia: A review

“…Reports mchcate that it is a satisfactory sedative m the young and in t_ae aged, but it should be used with some caution as a few cases of poisoning have been reported (105)(106)(107)(108)(109) Ethylchlorvynol (Placidyl| is a new nX~n-barbl~rate hypnotic of tertiary tinsaturated carbmol which was recendy introduced by the Abbott Laboratories. This drug was the most actave of a senes of chlormated carbinols with sedative effects (110,111). It is said to exlnblt a hypnotic effect superior to that of the unhalogenated acetylenic carbmols.…”

A Versatile and Highly Efficient Method for 1‐Chlorination of Terminal and Trialkylsilyl‐Protected Alkynes

“…[4] A typical reaction pathway proceeds through a deprotonated alkyne and prevents the use of some functional groups, for example the hydroxyl group. Other important routes towards the synthesis of 1-chloroalkynes include the chlorination of terminal alkynes by using hypochlorites, [5] the use a AgOAc/NCS (Ac = acetyl, NCS = N-chlorosuccinimide) system [6] or a CCl 4 /K 2 CO 3 /TBAF (TBAF = tetrabutylammonium fluoride) system, [7] and the use of phase-transfer catalysis. [8] The use of terminal alkynes, although common, can sometimes be problematic because these compounds can be unstable, especially long homologs.…”