Compounds of the formula ##STR1## wherein A is ##STR2## where R.sub.1 is hydrogen or alkyl of 1 to 3 carbon atoms; R.sub.2 is alkoxy of 1 to 3 carbon atoms;R.sub.3 is alkoxy of 1 to 3 carbon atoms or, together with R.sub.2, methylenedioxy or ethylenedioxy;R.sub.4 is hydrogen, alkyl of 1 to 3 carbon atoms or benzyl;R.sub.5 is hydrogen or alkyl of 1 to 3 carbon atoms;R.sub.6 is hydrogen or alkoxy of 1 to 3 carbon atoms;R.sub.7 is alkoxy of 1 to 3 carbon atoms or, together with R.sub.6, methylenedioxy or ethylenedioxy; andN is 2 or 3;And non-toxic, pharmacologically acceptable acid addition salts thereof; the compounds as well as their salts are useful as heart rate reducers and mild antihypertensives.This invention relates to novel N-(phenylalkylaminoalkyl)-substituted quinazolinones and phthalazinones and nontoxic acid addition salts thereof, as well as to various methods of preparing these compounds.More particularly, the present invention relates to a novel class of N-substituted quinazolinones and phthalazinones represented by the formula ##STR3## wherein A is ##STR4## where R.sub.1 is hydrogen or alkyl of 1 to 3 carbon atoms; R.sub.2 is alkoxy of 1 to 3 carbon atoms;R.sub.3 is alkoxy of 1 to 3 carbon atoms or, together with R.sub.2, methylenedioxy or ethylenedioxy;R.sub.4 is hydrogen, alkyl of 1 to 3 carbon atoms or benzyl;R.sub.5 is hydrogen or alkyl of 1 to 3 carbon atoms;R.sub.6 is hydrogen or alkoxy of 1 to 3 carbon atoms;R.sub.7 is alkoxy of 1 to 3 carbon atoms or, together with R.sub.6, methylenedioxy or ethylenedioxy; andN is 2 or 3;Or a non-toxic, pharmacologically acceptable acid addition salt thereof.A preferred sub-genus thereunder is constituted by compounds of the formula I whereR.sub.1 and R.sub.5 are each hydrogen, methyl, ethyl, n-propyl or isopropyl;R.sub.4 is hydrogen, methyl, ethyl, n-propyl, isopropyl or benzyl;R.sub.2, r.sub.3 and R.sub.7 are each methoxy, ethoxy, n-propoxy or isopropoxy;R.sub.6 is hydrogen, methoxy, ethoxy, n-propoxy or isopropoxy;R.sub.2 and R.sub.3, together with each other, are methylenedioxy or ethylenedioxy;R.sub.6 and R.sub.7, together with each other, are methylenedioxy or ethylenedioxy; andn is 2 or 3;and non-toxic, pharmacologically acceptable acid addition salts thereof.A further, especially preferred sub-genus thereunder is constituted by compounds of the formula I whereR.sub.2 and R.sub.3 are methoxy in the 6- and 7-position, respectively, or, together with each other, methylenedioxy or ethylenedioxy;R.sub.4 is hydrogen or methyl;R.sub.5 is hydrogen;R.sub.6 is hydrogen or methoxy in the 3-position;R.sub.7 is methoxy in the 4-position or, together with R.sub.6, methylenedioxy or ethylenedioxy; andn is 2 or 3;and non-toxic, pharmacologically acceptable acid addition salts thereof.The compounds embraced by formula I may be prepared by the following methods:Method ABy reacting a compound of the formula ##STR5## wherein R.sub.2, R.sub.3, A and n have the same meanings as in formula I, andZ is a leaving-group, such as chlorine, bromine, iodine, alkylsulfonyloxy or arylsulfonyloxy,with a phenylalkylamine of the formula ##STR6## wherein R.sub.4, R.sub.5, R.sub.6 and R.sub.7 have the same meanings as in formula I.The reaction is carried out in an inert solvent, such as ether, tetrahydrofuran, methylformamide, dimethylformamide, dimethylsulfoxide, chlorobenzene or benzene, and depending upon the reactivity of substituent Z, at a temperature between -50 and +250.degree. C, but preferably at the boiling point of the particular solvent which is used. The presence of an acid-binding agent, such as an alkali metal alcoholate, an alkali metal hydroxide, an alkali metal carbonate, especially potassium carbonate, or a tertiary organic base, particularly triethylamine or pyridine, or of a reaction accelerator, such as potassium iodide, is of advantage.Method BBy reacting a compound of the formula ##STR7## wherein A, R.sub.2 and R.sub.3 have the same meanings as in formula I, with a phenylalkylamine of the formula ##STR8## wherein R.sub.4, R.sub.5, R.sub.6 and n have the same meanings as in formula I, andZ has the same meanings as in formula II.The reaction is carried out in an inert solvent, such as acetone, dimethylformamide, dimethylsulfoxide or chlorobenzene, and, depending upon the reactivity of substituent Z, at a temperature between 0 and 150.degree. C, but preferably at the boiling point of the particular solvent which is used. The presence of an acid-binding agent, such as an alkali metal alcoholate, an alkali metal hydroxide, an alkali metal carbonate, especially potassium carbonate, an alkali metal amide or a tertiary organic base, particularly triethylamine or pyridine, or of a reaction accelerator, such as potassium iodide, is of advantage.Method CBy reacting an aldehyde of the formula ##STR9## wherein R.sub.2, R.sub.3, A and n have the same meanings as in formula I, or an acetal thereof, with an amine of the formula III in the presence of catalytically activated hydrogen.The reductive amination is carried out with hydrogen in the presence of a hydrogenation catalyst, such as palladized charcoal, at a hydrogen pressure of 5 atmospheres, in a solvent, such as methanol, ethanol or dioxane, and at a temperature between 0 and 100.degree. C, but preferably between 20 and 80.degree. C.Method DBy reacting an amine of the formula ##STR10## wherein R.sub.2, R.sub.3, R.sub.4, A and n have the same meanings as in formula I, with a phenylalkyl compound of the formula ##STR11## wherein R.sub.5, R.sub.6 and R.sub.7 have the same meanings as in formula I, andZ has the same meanings as in formula II.The reaction is carried out in an inert solvent, such as acetone, methylene chloride, dimethylformamide, dimethylsulfoxide or chlorobenzene, and, depending upon the reactivity of substituent Z, at a temperature between 0 and 150.degree. C, but preferably at the boiling point of the particular solvent which is used. The presence of an acid-binding agent, such as an alkali metal alcoholate, an alkali metal hydroxide, an alkali metal carbonate, especially potassium carbonate, or a tertiary organic base, particularly triethylamine or pyridine, or of a reaction accelerator, such as potassium iodide, is of advantage.Method EFor the preparation of a quinazolinone derivative of the formula I, by reacting a benzoxazin-4-one of the formula ##STR12## wherein R.sub.1, R.sub.2 and R.sub.3 have the same meanings as in formula I, with an alkylenediamine of the formula wherein R.sub.4, R.sub.5, R.sub.6 and R.sub.7 have the same meanings as in formula I.The reaction is advantageously carried out in a solvent, such as benzene, dioxane, a lower alkanoic acid such as glacial acetic acid, or dimethylformamide, and optionally in the presence of an acid catalyst at a temperature between 50 and 150.degree. C, but preferably at the boiling point of the particular solvent which is used. The preferred solvent is glacial acetic acid. The reaction may, however, also be performed without a solvent.If the end product of methods A through E is a compound of the formula I wherein R.sub.4 is benzyl, the same may be de-benzylated to yield the corresponding compound wherein R.sub.4 is hydrogen. The de-benzylation is preferably effected by means of catalytic hydrogenation, for example with hydrogen in the presence of a catalyst such as palladized charcoal, in a solvent such as ethanol or ethylacetate, at a temperature between 25 and 75.degree. C and at a hydrogen pressure of 1 to 7 atmospheres.On the other hand, if the end product of methods A through E is a compound of the formula I wherein R.sub.4 is hydrogen; the same may be alkylated at the bridge nitrogen atom to form the corresponding compound where R.sub.4 is alkyl. The alkylation is carried out with a conventional alkylating agent, for example with an alkyl halide such as methyl iodide, ethyl iodide or isopropyl bromide, or with a dialkylsulfate such a dimethylsulfate, in a solvent such as acetone, dimethylformamide or dioxane, optionally in the presence of an inorganic or tertiary organic base, at a temperature between 0 and 50.degree. C. A methylation may also be effected by reaction with a mixture of formaldehyde and formic acid, preferably at the boiling point of said mixture.The compounds embraced by formula I are organic bases and therefore form acid addition salts with inorganic or organic acids. Examples of non-toxic, pharmacologically acceptable acid addition salts are those formed with hydrochloric acid, phosphoric acid, hydrobromic acid, sulfuric acid, lactic acid, tartaric acid, maleic acid, 8-chlorotheophylline or the like.The starting compounds of the formulas II through X are either described in the literature or may be prepared by known methods, as described in the examples below.