66016-19-1

The present application discloses a compound of formula (I) or a salt thereof: (I) and compositions comprising such compound or salt thereof. The use of such compound, salt thereof or composition comprising same for treating anemia or leukopenia, fibrosis, cancer, hypertension and/or a metabolic condition in a subject is also disclosed.

An optically inactive cyclobutanecarboxylic acid derivative of the general formula STR1 wherein R1 is a hydrogen atom or a straight or branched chain alkyl group having 1-14 carbon atoms, R2 is a straight or branched chain alkyl grou

The preparation of sixteen dimethylene linked compounds is described heptane ring>, and a comparison is made between the transition temperatures of these compounds and those of the corresponding esters.This comparison once again highlights the fact that the cyclobutane ring should be regarded, in terms of its ability to promote nematic thermal stability, as a "chain stiffener rather than as a ring system.A comparison is also made of the nematic thermal stabilities of the trans-cyclobutane and the spiroheptane systems and of the trans-cyclohexane and the spiroundecane systems.

A number of esters of structure (I) incorporating the cyclobutane, spiroheptane, or dispirodecane rings has been prepared using a diethyl malonate synthesis.Strict comparison of the liquid crystal behaviour amongst the three classes containing a terminal cyano-substituent was not possible because both the cyclobutanes and dispirodecanes are mixtures of cis- and trans-isomers; the spiroheptanes are racemic systems.Using preparative hplc, it was however possible to isolate the pure cis- and trans-isomers of two of the cyano-substituted cyclobutane esters (I; R = alkyl, -X- = --, Y = CN).From the physical data and the results for the corresponding spiroheptane esters, conclusions regarding the effects of these ring systems on liquid crystal behaviour were obtained.The pure cis- and trans-isomers of the cyclobutane ester (I, R = C3H7, -X- = --, Y = CN) have been assessed for the trends in both order parameter and viscosity with temperature; the results support the idea that idea that the trans-cyclobutane ring adopts a more planar conformation at higher temperatures.Keywords: cyclobutane- and related spiro-systems, cis-/trans-isomerism, order parameter, briefringence, viscosity, structure/property relations.

Antiinflammatory and analgesic activities of 3 substituted cyclobutanecarboxylic acids are pointed out and their structure-activity relationship examined according to the Hansch method. This analysis shows the influence of the steric and lipophilic parameters and this quantitative basis let us realize the synthesis of two acids, the analgesic acitivities of which are very much improved. Attempted quantitative correlations between physiochemical parameters and antiinflammatory activity were unsuccessful. This is imputable to a too imprecise representation of the steric effect which plays a primordial part in this kind of activity.