Abstract: In a solar heat powered plant according to the present invention, hot water is normally circulated through a hot-water tank, a low-temperature-side heat load unit, a return tank, a low-temperature-side heat exchanger, and again through the hot-water tank, in the order named, under the condition in which first and second valves are opened and closed, respectively. On the other hand, in warming up the hot-water tank, the first and second valves are closed and opened, respectively, so that the hot water is circulated between the hot-after tank and the low-temperature-side heat exchanger, through a by-pass pipe. Thus, the warming up of the hot-water tank can be achieved in a short time.

Abstract: 1,4-Benzodiazepine derivatives of the formula: ##STR1## (in which R.sup.1 is pyrrolidinyl or piperidinyl each optionally substituted by C.sub.1-3 alkyl, phenyl-C.sub.1-3 alkyl, C.sub.1-5 alkanoyl, or C.sub.2-5 alkoxycarbonyl,R.sup.2 is hydrogen, hydroxy, or acetoxy,R.sup.3 is C.sub.1-3 alkyl, phenyl-C.sub.1-3 alkyl, or phenyl optionally substituted by one or two halogens,X is hydrogen, halogen, C.sub.1-3 alkyl, C.sub.1-3 alkoxy, nitro, trifluoromethyl, or di-C.sub.1-3 alkyl-amino, andn is 1 or 2)or pharmaceutically acceptable acid addition salts thereof, which are useful as a psychotropic agent such as anti-depressant or anxiolytic agent can be prepared from several routes.

Abstract: O-Aminophenyl ketone derivatives are regio-specifically prepared by reacting an aniline unsubstituted in at least one ortho position with a nitrile in the presence of boron trihalogenide to introduce a substituted iminomethyl into the ortho position of said aniline and hydrolyzing the resulting iminomethyl compound.