A new class of spiro-pyrimidines, pyrazoles and isoxazoles are prepared by nucleophilic reaction of 3,5-diaroyl-2,6-diaryl-piperidine-4,4-dicarbonitrile (1), 3,5-diaroyl-2,6-diaryl-tetrahydropyran-4,4-dicarbonitrile (2) and 3,5-diaroyl-2,6-diaryl-tetrahydrothiopyran-4,4-dicarbonitrile (3) with urea, N,N'-dimethyl urea, thiourea, hydrazine hydrate and hydroxylamine hydrochloride.J. Heterocyclic Chem., 41, 951 (2004).In recent years we have been actively involved in the synthesis of spiro-heterocycles by the reaction of carbocycle-or heterocycle-1,1-dicarboxylic esters with various nucleophiles [1][2][3][4][5][6]. Prompted by the successful results on this front, we present in this article the utilization of compounds having gem-dicyano functionality in the synthesis of spiro-heterocycles by the cyclocondensation of former with various nucleophiles viz, urea, N,N′-dimethyl urea, thiourea, hydrazine hydrate and hydroxylamine hydrochloride.The 3,5-diaroyl-2,6-diaryl-piperidine-4,4-dicarbonitrile (1), 3,5-diaroyl-2,6-diaryl-tetrahydropyran-4,4-dicarbonitrile (2) and 3,5-diaroyl-2,6-diaryl-tetrahydrothiopyran-4,4-dicarbonitrile (3) are prepared by the reaction of 2,2-bis(1-benzoyl-2-phenyl-vinyl)-malononitrile with NH 4 OAc, P 2 O 5 and P 2 S 5 [7]. The cyclocondensation of 1, 2 and 3 with urea in the presence of NaOMe gave 1,5-diamino-7,11-dibenzoyl-8,10-diphenyl-2,4,9-triazaspiro[5.5]undeca-1,4-dien-3-one (4) 1,5-diamino-7,11-dibenzoyl-8,10-diphenyl-9-oxa-2,4-diazaspiro[5.5]-undeca-1,4-dien-3-one (5) and 1,5-diamino-7,11-dibenzoyl-8,10-diphenyl-9-thia-2,4-diazaspiro[5.5]undeca-1,4-dien-3-one (6). Similar reaction of 1, 2 and 3 with N,N′-dimethyl urea and thiourea afforded 7,11-dibenzoyl-1,5-diimino-2,4-dimethyl-8,10-diphenyl-2,4,9-triazaspiro[5.5]undecan-3-one (7), 7,11-dibenzoyl-1,5-diimino-2,4-dimethyl-8,10-diphenyl-9-oxa-2,4-diazaspiro[5.5]-undecan-3-one (8), 7,11-dibenzoyl-1,5-diimino-2,4-dimethyl-8,10-diphenyl-9-thia-2,4-diazaspiro[5.5]undecan-3-one (9) and 1,5-diamino-7,11-dibenzoyl-8,10-diphenyl-2,4,9-triazaspiro[5.5]undeca-1,4-dien-3-thione (10), 1,5-diamino-7,11-dibenzoyl-8,10-diphenyl-9-oxa-2,4-diazaspiro[5.5]undeca-1,4-dien-3-thione (11), 1,5-diamino-7,11-dibenzoyl-8,10-diphenyl-9-thia-2,4-diazaspiro[5.5]-undeca-1,4-dien-3-thione (12), respectively. Likewise, five membered spiro heterocycles, 1,4-diamino-6,10-dibenzoyl-7,9-diphenyl-2,3,8-triazaspiro[4.5]deca-1,3-diene (13), 1,4-diamino-6,10-dibenzoyl-7,9-diphenyl-8-oxa-2,3-diazaspiro[4.5]deca-1,3-diene (14), 1,4-diamino-6,10-dibenzoyl-7,9-diphenyl-8-thia-2,3-diazaspiro[4.5]deca-1,3-diene (15) and 4-amino-6,10-dibenzoyl-7,9-diphenyl-1-imino-2-oxa-3,8-diazaspiro[4.5]deca-3-ene (16), 4-amino-6,10-dibenzoyl-7,9-diphenyl-1-imino-2,8-dioxa-3-azaspiro[4.5]deca-3-ene (17), 4-amino-6,10-dibenzoyl-7,9-diphenyl-1-imino-2-oxa-8-thia-3-azaspiro[4.5]deca-3-ene (18) were prepared by refluxing 1, 2 and 3 with hydrazine hydrate and hydroxylamine hydrochloride, respectively (Scheme & Table 1). Though there is a possibility of diastereoisomers particularly in compounds 16-18...
