Abstract: A following dipeptide derivative of the following formula (I) is provided, which is capable of inhibiting the enzymatic activity of renin and thereby depressing the renin-angiotensin system and lowering the blood pressure. ##STR1## wherein: R.sup.1 is C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.10 cycloalkyl, aryl, or heterocyclic radical;R.sup.2 is carbamoyl, aryl, 5- or 6-membered heterocyclic radical, C.sub.1 -C.sub.12 alkyl-S--, C.sub.1 -C.sub.12 alkyl-S--CH.sub.2 --, or C.sub.3 -C.sub.10 cycloalkyl-S--;R.sup.3 is aryl or 5- or 6-membered heterocyclic radical;R.sup.4 is R.sup.4' --SO.sub.2 or R.sup.4' --CO;R.sup.4' is aryl, C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl; C.sub.3 -C.sub.10 cycloaklyl, or heterocyclic radical;X is CH.sub.2, NH, O, or S; andY is CO or NHSO.sub.2, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4' each may be substituted with one to three substituents.

Abstract: A dipeptide derivative of the formula (I) is provided, which is capable of inhibiting the enzymatic activity of renin and thereby depressing the renin-angiotensin system and lowering the blood pressure, provided. ##STR1## wherein: R.sup.1 is C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.10 cycloalkyl, aryl, or heterocyclic radical;R.sup.2 is carbamoyl, aryl, 5- or 6-membered heterocyclic radical, C.sub.1 -C.sub.12 alkyl-S--, C.sub.1 -C.sub.12 alkyl-S--CH.sub.2 -, or C.sub.3 -C.sub.10 cycloalkyl-S-;R.sup.3 is aryl or 5- or 6-membered heterocyclic radical;R.sup.4 is R.sup.4' --SO.sub.2 or R.sup.4' --CO;R.sup.4' is aryl, C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl; C.sub.3 -C.sub.10 cycloalkyl, or heterocyclic radical;X is CH.sub.2, NH, O, or S; andY is CO or NHSO.sub.2, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4' each may be substituted with one to three substituents.

Abstract: A dipeptide derivative of formula (I) is provided, which is capable of inhibiting the enzymatic activity of renin and thereby depressing the renin-angiotensin system and lowering the blood pressure. ##STR1## wherein: R.sup.1 is C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.10 cycloalkyl, aryl, or heterocyclic radical;R.sup.2 is carbamoyl, aryl, 5- or 6-membered heterocyclic radical, C.sub.1 -C.sub.12 alkyl-S--, C.sub.1 -C.sub.12 alkyl-S--CH.sub.2 --, or C.sub.3 -C.sub.10 cycloalkyl-S--;R.sup.3 is aryl or 5- or 6-membered heterocyclic radical;R.sup.4 is R.sup.4' --SO.sub.2 or R.sup.4' --CO;R.sup.4' is aryl, C.sub.1 -C.sub.12 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl; C.sub.3 -C.sub.10 cycloalkyl, or heterocyclic radical;X is CH.sub.2, NH, O, or S; andY is CO or NHSO.sub.2, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4' each may be substituted with one to three substituents.

Abstract: A method of producing a reinforced ceramic which includes a step of aggregating ceramic fibrous material of 0.5 .mu.m or more in diameter; a composite step in which the fiber aggregate obtained is placed on a filter and a dispersion liquid in which ceramic powder having a particle size of not more than one-tenth of the diameter of the ceramic fibrous material is dispersed in a dispersion medium is transferred through the fiber aggregate from a side opposite to the filter to the other side, for passing the dispersion medium through said filter and introducing the ceramic powder in a gap between the fibrous material of the fiber aggregate to form a composite of the fibrous material and the ceramic powder; and a step of sintering the composite.

Abstract: A new process for production of 2-haloacetylphenols having the general formula ##STR1## (wherein, Y is halogen atom;m is an integer of 0-2,X and n have the same meaning as mentioned below),which comprises reacting phenols having the general formula ##STR2## (wherein, X is hydrogen, C.sub.1 -C.sub.5 alkyl, C.sub.3 -C.sub.6 cycloalkyl, C.sub.1 -C.sub.5 alkoxy or halogen atom;n is an integer of 0-2)with haloacetonitriles and boron halide compounds in the presence of condensing coagents.

Abstract: Cyanopinacolone is produced by reacting pinacolone with about 1.0 to about 1.2 molar equivalents of chlorine in methanol and further reacting the resulting monochloropinacolone with about 1.0 to about 1.2 molar equivalents of an alkali metal cyanide in methanol.

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.