FIELD: chemical industry. SUBSTANCE: novel aryl condensed 2,4- diazepine compounds of formula I: 
wherein A is napthyl, phenyl, unsubstituted or substituted by halogen, nitro, lower alkyl or alkoxy; R1 is H, lower alkyl or phenyl; R2 is H, lower alkyl, cyclopropyl (lower alkyl, benzyl, phenyl, unsubstituted or substituted by lower alkoxy; or -CH2CH2R7 wherein R7 is lower alkoxy, di(lower) alkylamino or morpholino; R3 is Yp-(CH2)m-Xn-R8 wherein J is NH-, - S-, -O- or -CH(CH3), p=0 or 1, m=0-7, n= 0-1; A is -S-, -O-, O2 or -CH=CH; R8 is H, lower alkyl, phenyl, pyridinyl optionally substituted by lower alkyl; phenyl with 1 or 2 substituents selected from halogen, lower alkyl, lower alkoxy, lower alkyl sulfonamide, di(lower)alkyl aminosulfonyl; R4 is H, lower alkyl or lower alkoxyalkyl; 
is H, lower alkyl, benzyl, phenyl optionally substituted by halogen or lower alkoxy, or naphthyl. Said compounds have antiarrythmic activity. Antiarrythmic agent is used in combination with pharmaceutically acceptable solvent or filler in composition for treating heart arrythmia. The present invention describes novel intermediate compounds: 
wherein R1a is H, lower alkyl or phenyl; R5a is H, phenyl optionally substituted by halogen or lower alkoxy, or napthyl; R6 is halogen or condensed benzene ring: R9 is H, lower alkyl, benzyl or di(lower)alkylamino (lower) alkyl; R10 is H, lower alkyl, phenyl optionally substituted by halogen, lower alkyl, lower alkoxy, lower alkyl sulfonamide, or pyridinyl unsubstituted or substituted by lower alkyl; n is 0 or 1; R2a is lower alkyl, benzyl, phenyl optionally substituted by lower alkoxy; or CH2CH2R7 in which R7 is lower alkoxy, di(lower)alkylamino or morpholino; R5a is H, benzyl, naphthyl, phenyl optionally substituted by halogen, lower alkoxy. Said compounds are used for synthesizing compounds of general formula I. EFFECT: improved properties of the title compounds. 12 cl, 275 ex, 1 tbl
