Abstract: A compound of the following formula (II) and a process for preparing of the compound of the following formula (I) its preparation wherein R1 is carboxy or protected carboxy; R2 is lower alkoxy or higher alkoxy; A1 is a divalent aromatic ring, a divalent heterocyclic group or a divalent cyclo(lower)alkane; and A2 is a divalent aromatic ring, a divalent heterocyclic group or a divalent cyclo(lower)alkane, or a salt thereof. The process comprises, reacting a compound of the formula (III): wherein R1, R2, A1 and A2 are each as defined above or a salt thereof, with an acid ammonium salt to give a compound of the formula (II).

Abstract: A new industrial process excellent in yield and purity for preparing a compound of the formula: or a salt thereof in a less number of steps with a synthetic pathway without proceeding via nitroso compounds, wherein R1 is lower aryl, ar(lower)alkoxy or heterocyclic group, each of which may be substituted with halogen, and R2 is cyclo(lower)alkyl, aryl or ar(lower)alkyl, each of which may be substituted with halogen.

Abstract: This invention provides an industrially useful process for producing a quinazoline derivative (I) of the general formula: [wherein R1 is hydrogen or halogen; R2 is carboxy or protected carboxy; A is lower alkylene] or its salt on a commercial scale which comprises reacting a compound of the general formula: [wherein R1 is hydrogen or halogen] or its salt with a silylating agent and then with a compound of the general formula: Cl—A—R2  (III) [wherein R2 is carboxy or protected carboxy; A is lower alkylene] or its salt, optionally followed by desilylation.

Abstract: A compound of formula (1) or a salt thereof: wherein R1 is a carboxy or a protected carboxy; R2 is a lower alkoxy or a higher alkoxy; A1 is a divalent aromatic ring, a divalent heterocyclic group or a divalent cyclo(lower)alkane; and A2 a divalent aromatic ring, a divalent heterocyclic group or a divalent cyclo(lower)alkane; is prepared by reacting a compound of formula (III) or a salt thereof with acid ammonium salt: wherein R1, R2, A1 and A2 are each as defined above; to give a compound of formula (II) or a salt thereof which is further reacted with a salt of hydroxylamine: wherein R1, R2, A1 and A2 are each as defined above.

Abstract: The present invention relates to a novel process for preparing of the compound of the following formula (I)

Abstract: A process for producing pyridiondole derivatives represented by general formula (III) or their salts (wherein R.sup.1 represents hydrogen, lower alkyl or lower alkenyl; R.sup.2 represents hydrogen, lower alkyl or halogeno; and R.sup.3 represents optionally substituted imidazolyl), which comprises reacting a compound represented by general formula (I) or its salt (wherein R.sup.1 and R.sup.2 are each as defined above) with a compound represented by general formula (II) or its salt (wherein R.sup.3.sub.a represents optionally substituted imidazolyl having an imino protecting group; and X represents halogeno), followed by a reaction for eliminating the imino protecting group); and a process for producing optically active pyridoindole derivatives represented by general formula (IV) or their salts: which comprises reacting a racemic mixture of the pyridoindole derivative represent by formula (III) or its salt with (1R)-(-)-10-camphorsulfonic acid.

Abstract: The present invention relates to synthetic intermediates useful for preparing amino acid derivatives possessing renin-inhibitory activity, and to processes for preparing the amino acid derivatives using the synthetic intermediates.

Abstract: The present invention relates to a process for producing (.+-.)-(E)-4-ethyl-2-[E-hydroxyimino]-5-nitro-3-hexenamide.