Disclosed is a method of preparing propylene including the step of irradiating propane in the presence of a catalyst containing a decatungstate salt and a co-catalyst, in which the co-catalyst has cobalt or nickel. Also provided are catalysts and methods of dehydrogenating alkanes.

A process for the preparation of a compound of formula (I):

##STR00001## comprising the reaction of:

R.sup.1C(O)NHNHC(O)R.sup.2, with R.sup.3CH.sub.2CH.sub.2OCH.sub.2CH.sub.2R.sup.4, in the presence of an alcoholic solvent; wherein R.sup.1 and R.sup.2 are independently selected from straight or branched chain alkyl groups, or are bonded to form a 4, 5, or 6-membered heterocycle, and wherein R.sup.3 and R.sup.4 are independently selected from a halide or a sulphate.

A powder coating composition comprising an acid functional polyester resin A formed by reacting one or more polyol constituents, wherein at least 90 mole % of the polyols constituents is neopentylglycol, with one or more poly acid constituents wherein at least 87 mole % of the poly acid constituents is isophthalic acid (IPA); wherein polyester resin A has an Acid Number (AN) of between 20 and 90 mg KOH/g; and a hydroxyl value of less than 50, preferably less than 15 mg KOH/g; a glycidyl functional acrylic resin B having a weight average molecular weight of between 2500 and 7000; a curing catalyst C capable of catalyzing the reaction between the polyester resin A and the acrylic resin B; and optionally -hydroxyalkylamide D.