microanalytical data , h - nmr and mass spectra of the compounds were recorded at the regional sophisticated instrumentation center , central drug research institute ( rsic , cdri ) , lucknow . the fab mass spectrum of the complex was recorded on a jeol sx 102/da-6000 mass spectrometer / data system using argon / xenon ( 6 kv , 10 ma ) as the fab gas . the accelerating voltage was 10 kv and the spectra were recorded at room temperature using m - nitrobenzylalcohol ( nba ) as the matrix . the ir spectra of the samples were recorded on a perkin - elmer 783 spectrophotometer in 4000~400 cm range using kbr pellet . a mixture of m - nitrobenzaldehyde ( l)/p - methoxybenzaldehyde ( l)/benzaldehyde(l)/o - hydroxybenzaldehyde ( l ) , thiourea and ethylacetoacetate in presence of ammonium dihydrogen phosphate was stirred for 2 h in ethanol . the solid product was filtered and washed with water and dried ( fig . 2 ) . where r - ch2ch3 ; x =- no2(l ) ; -och3(l ) ; aspergillus flavus , trichoderma viride , trichoderma harzianum and sclerotium rolfsii were isolated from the soil sample by serial dilution and pour plate techniques . the fungi were maintained in the potato dextrose agar plates ( pda ) and stored at 4. a. niger , a. flavus , t. viride , t. harzianum and s. rolfsii were employed for the testing of the antifungal activity using the cup - plate method . the culture was maintained on sabouraud 's agar for 72 h , which gave the optimum growth of the test fungal spores . all the purified compounds were loaded with different concentrations ( g / ml ) ( tables 2~5 ) and kept in a sterile petri dish . the inoculum consisted of an overnight - grown broth culture of different fungi diluted in such a manner that a 2 mm ( internal diameter ) loopful of the cultures containing 10 colony - forming units ( cfu ) . then the cultures were inoculated on sabouraud 's agar plates and incubated at 37 for upto 48 h to determine the minimum inhibitory concentration ( mic ) . a mixture of m - nitrobenzaldehyde ( l)/p - methoxybenzaldehyde ( l)/benzaldehyde(l)/o - hydroxybenzaldehyde ( l ) , thiourea and ethylacetoacetate in presence of ammonium dihydrogen phosphate was stirred for 2 h in ethanol . the solid product was filtered and washed with water and dried ( fig . 2 ) . where r - ch2ch3 ; x =- no2(l ) ; -och3(l ) ; aspergillus niger , aspergillus flavus , trichoderma viride , trichoderma harzianum and sclerotium rolfsii were isolated from the soil sample by serial dilution and pour plate techniques . the fungi were maintained in the potato dextrose agar plates ( pda ) and stored at 4. a. niger , a. flavus , t. viride , t. harzianum and s. rolfsii were employed for the testing of the antifungal activity using the cup - plate method . the culture was maintained on sabouraud 's agar for 72 h , which gave the optimum growth of the test fungal spores . all the purified compounds were loaded with different concentrations ( g / ml ) ( tables 2~5 ) and kept in a sterile petri dish . the inoculum consisted of an overnight - grown broth culture of different fungi diluted in such a manner that a 2 mm ( internal diameter ) loopful of the cultures containing 10 colony - forming units ( cfu ) . then the cultures were inoculated on sabouraud 's agar plates and incubated at 37 for upto 48 h to determine the minimum inhibitory concentration ( mic ) . in the present investigation , biginelli type dihydropyrimidinones analogous were prepared from a reaction mixture consisting of substituted benzaldehydes , thiourea and ethylacetoacetate in presence of ammonium dihydrogen phosphate as catalyst . all the products were characterized by ir , h - nmr , mass spectral and elemental analytical data . the yields , melting points and the molecular mass of the compounds obtained from the mass spectral study are given in table 1 . the elemental analytical data of the compounds are in good agreement with the theoretical values which are given as follows : data of l : m.p . : c , 52.33 ; h , 4.67 ; n , 13.08% . found : c , 52.28 ; h , 4.62 ; n , 13.05 % . calc . for c15h18n2o3s : c , 58.82 ; h , 5.88 ; n , 9.15% . found : c , 58.78 ; h , 5.83 ; n , 9.13 % . : c , 60.87 ; h , 5.80 ; n , 10.14% . found : c , 60.83 ; h , 5.75 ; n , 10.10% . 178~180 ; anal . calc . for c14h16n2o3s : c , 54.54 ; h , 5.19 ; n , 9.09% . the ir spectra provide some information regarding the skeleton of the compounds and were analyzed by a careful comparison with that of the parent compounds . the sharp bands in the 750~790 and 1520~1540 cm regions are due to aromatic uc - h and uc = c , respectively . the band appearing at 1710 cm is assigned to the carbonyl group of the ethylacetoacetate moiety n(c = o ) of the compound . comparison of the h - nmr spectra of the compound ( l ) , recorded in cdcl3 ( fig . this compound ( l ) shows signals at 10.02 ( -nh ) , 8.15 ( -phnh ) , 7.50 ( -nh ) , 4.1 ( -ch ) , 3.12 ( -och3 ) , 2.44 ( -ch2 ) , 1.98 ( -ch3 ) , 1.50 ppm ( -ch3 ) . similarly , the other h - nmr spectra support the proposed skeleton of the compounds . based on the above data , the proposed structure of the compounds was given as shown in fig . 4 : the in vitro antifungal activity of the compounds was tested against filamentous fungi such as a. flavus , a. niger , t. harzianum , t. viride and s. rolfsii by cup - plate method . antifungal activities of all the compounds ( l~l ) were compared with known chosen standard fungicide like fluconazole . a comparative study of the compounds indicates that in general , compound l has higher activity than the other compounds . a. niger had resistant to compound l. variety of subtituents introduced on the organic part using heterocycles and ether -o- atom ( kaim and schwedersk , 1991 ) etc . , increase antimicrobial activity because this increases basic strength and furnishes delocalization of  - electrons over the whole rings . this increased activity can also be explained on the basis of overtone 's concept ( anjaneyula and rao , 1986 ) . according to overtone 's concept of cell permeability , the lipid membrane that surrounds the cell favours the passage of only the lipid - soluble materials due to which liposolubility is an important factor , which controls the antifungal activity . the ir spectra provide some information regarding the skeleton of the compounds and were analyzed by a careful comparison with that of the parent compounds . the sharp bands in the 750~790 and 1520~1540 cm regions are due to aromatic uc - h and uc = c , respectively . the band appearing at 1710 cm is assigned to the carbonyl group of the ethylacetoacetate moiety n(c = o ) of the compound . comparison of the h - nmr spectra of the compound ( l ) , recorded in cdcl3 ( fig . this compound ( l ) shows signals at 10.02 ( -nh ) , 8.15 ( -phnh ) , 7.50 ( -nh ) , 4.1 ( -ch ) , 3.12 ( -och3 ) , 2.44 ( -ch2 ) , 1.98 ( -ch3 ) , 1.50 ppm ( -ch3 ) . similarly , the other h - nmr spectra support the proposed skeleton of the compounds . based on the above data , the proposed structure of the compounds was given as shown in fig . 4 : the in vitro antifungal activity of the compounds was tested against filamentous fungi such as a. flavus , a. niger , t. harzianum , t. viride and s. rolfsii by cup - plate method . antifungal activities of all the compounds ( l~l ) were compared with known chosen standard fungicide like fluconazole . a comparative study of the compounds indicates that in general , compound l has higher activity than the other compounds . a. niger had resistant to compound l. variety of subtituents introduced on the organic part using heterocycles and ether -o- atom ( kaim and schwedersk , 1991 ) etc . , increase antimicrobial activity because this increases basic strength and furnishes delocalization of  - electrons over the whole rings . this increased activity can also be explained on the basis of overtone 's concept ( anjaneyula and rao , 1986 ) . according to overtone 's concept of cell permeability , the lipid membrane that surrounds the cell favours the passage of only the lipid - soluble materials due to
a simple , efficient and cost effective method is described for the synthesis of biginelli type heterocyclic compounds of dihydropyrimidinones analogous . 
 they were prepared from a reaction mixture consisting of substituted benzaldehydes , thiourea and ethylacetoacetate using ammonium dihydrogenphosphate as catalyst . 
 the procedure for the preparation of the compounds is environmentally benign and safe which is advantageous in terms of experimentation , catalyst reusability , yields of the products , shorter reaction times and preclusion of toxic solvents . 
 the four new synthesised compounds were tested for their antifungal activity . 
 they have good antifungal activity comparing to the standard ( fluconazole ) .