2- pyrimidin-4-one

Zinc dust has been used to reduce a tetrazole of the tricyclic system 57 to generate the corresponding bicyclic 2-amino-3,5,6-trimethyl-3//-thieno[2,3- /]pyrimidin-4-one 58 (Equation 8) <2000MOL835>. 

The Paal Knorr reaction provides an efficient synthesis of l,3,7-triaryl-6-phenyl-2-thioxo-l,2,3,7-tetrahydropyr-rolo[2,3- pyrimidin-4-one derivatives from 2-thiobarbituric acids under microwave conditions <2006JHC1231>. 

Cyclocondensation of 3 - c y a n o - 2 - m e t h y 11 h i o - 4 //- p y r i d o [ 1,2-a]pyrimidin-4-ones and ethyl mercaptoacetate in boiling EtOH in the presence of NaOEt afforded 4//-pyrido[l,2-a]thieno[2,3-(/]pyrimidin-4-ones 210 (00HC571). 2-Methylthio-4-oxo-4i7-pyrido[l,2-a]pyrimidine-3-carboxylates 211 and mercaptoacetates afforded tricyclic derivatives 212 (93MIP1). Cyclocondensation of 2-methylthio-4-oxo-4i/-pyrido[l,2-a]pyrimidin-3-car-bonitriles 213 with E NNE -E O and with guanidine El Cl afforded tricyclic derivatives 214 and 215, respectively (96FES781). 

Strong heating of 2-substituted 5-propargylsulfanyl-3-aryl-3//-pyrimidin-4-ones, and their 5-allylsulfanyl derivatives, has been shown to lead to 2-substituted 3-aryl-6-methyl-3//-thieno[3,2-d]pyrimidin-4-ones and their 6,7-dihydro derivatives. The proposed mechanism in both cases is a [3,3]-sigmatropic thia-Claisen rearrangement followed by tautomerization and a 5-exodig or 5-exo-trig cyclization.38... 

Diorganotin(IV) complexes with 4 -pyrido[l,2-<3]pyrimidin-4-ones 109 (96MI4), complexes of 2-methyl- and 2-methyl-8-nitro-9-hydroxy-4i/-pyrido[l,2-<2]pyrimidin-4-ones with Ag(I), Cu(II), Ni(II), Co(II), and Mn(II) ions (00MI23), 2,4-dimethyl-9-hydroxypyrido[l, 2-<2]pyrimidinium perchlorate and its complexes with prasedynium, neodymium, samarium and europium (00MI24) were characterized by UV spectroscopy. 

In the series of reactions the chloro atom of 2-chloro-4 -pyrido[l,2-<3]pyrimidin-4-ones was substituted by different primary and cyclic amines (93FES1225, 95EJM27, 00BMC751, 01MIP9), and by ethylenediamine and... 

Methoxy-4F7-pyrido[l,2- z]pyrimidin-4-one was prepared from 2-chloro-4F7-pyrido[l,2-<3]pyrimidin-4-one with NaOMe in MeOH for 16h, and from <3f7/zy /r6>-(2-hydroxy-4-oxo-4F7-pyrido[l, 2- z]pyridinium)hydroxide with Me2S04 in the presence of NaOMe in MeOH for 3h at room temperature in 93% and 41% yields, respectively (99JCS(P2)1087). 2-(2-Hydroxyethoxy)-4F7-pyrido[l,2-a]pyrimidin-4-one was prepared from the... 

Treatment of 9-(ethoxymethoxy)-3- 2-[4-(6-fiuoro-l, 2-benzisoxazol-3-yl)-1,2,5,6-tetrahydro-1 -pyridyl] and -1 -piperidyl]ethyl -2-methyl-4 -pyrido-[l,2-<3]pyrimidin-4-ones with cone. HCl afforded 9-hydroxy derivatives (95MIP4, OOMIPIO). 

Risperidone (11) was prepared starting from 3-(2-chloroethyl) 180, via 3-(2-aminoethyl) 181, and 3- 2-[4-(2,4-difiuorobenzoyl)piperidino]ethyl 182 derivatives of 4 -pyrido[l,2-<3]-pyrimidin-4-ones as depicted in Scheme 11 (94MIP8, 95MIP7). 

Reaction of 7-bromo-2-butoxy-3-phenyl-4Ff-pyrido[l,2-<3]pyrimidin-4-one (203, R = Bu, Ar = Ph) and (4-ClPh)BH2 in the presence of a 2 M solution of Na2C03 and (Ph3P)4Pd afforded 7-(4-chlorophenyl) derivative... 

Reaction of 2-(A -allylamino)-3-formyl-4 -pyrido[l,2-<3]pyrimidin-4-ones 219 in EtOH with HONH2-HC1 yielded ( )-oximes 220 at 0°C and 221 (R = PhCH2) under reflux. Heating 220 (R = H) in a boiling solvent afforded c/A-fused tetracyclic cycloadducts 221 (R = H). In an aprotic solvent (e.g., benzene or MeCN) the main cw-fused cycloadducts 221 (R =H) were accompanied by a mixture of trans-fw Qd cycloadducts 222, 77-oxides 223 and tetracyclic isoxazoline 224 (96T887). The basicity of the 2-allylamino moiety of compounds 219 affected the rate of the conversion. Cycloadditions were also investigated in dioxane and BuOH. 

Het)aryl-l,4-dihydro-l,8-naphthyridin-4-ones 288 were obtained by heating 2-(het)aryl-4 -pyrido[l,2-<3]pyrimidin-4-ones 287 at 350 °C (97JMC2266, 99JMC4081) and in Dowtherm A at 220-240 °C... 

Cyclization of 4-[(2-pyridylamino)methylene]-2-methoxythiazolin-5(4 -one 313 (R = Me) in the presence of NaOMe gave 3-(methoxythiocarbo-nylamino)-4i/-pyrido[l,2-<3]-pyrimidin-4-one 314. When the reaction mixtures were subsequently treated with Mel, and the evaporated reaction mixtures with cone. HCI in EtOH, 3-amino-4E7-pyrido[l,2- z]pyrimidin-4-ones 315 were obtained (94JHC125). 

Reaction of 2 equiv of 2-aminopyridines with 2-hydropolyfluoroalk-2-anoates 351 in MeCN in the presence of NEt3 at 90 °C for 50 h afforded a mixture of the isomeric 2-oxo-2H- and 4-oxo-4Ef-pyrido[l,2-<3]pyrimidines 110 and 111. Reaction of 3 equiv of 2-amino-pyridines and 2-hydropoly-fluoroalk-2-enoates 351 in MeCN in the presence K2CO3 could be accelerated by ultrasonic irradiation (125 W). 2-Amino-6-methylpyridine yielded only 2-substituted 6-methyl-4Ef-pyrido[l,2-<3]pyrimidin-4-ones 111 (R = 6-Me), whereas 2-amino-5-bromopyridine gave a mixture of 7-bromo-4//-pyrido[l,2- jf]pyrimidin-4-one (111, R = 7-Br, R = CF2C1) and 2-(chlor-o,difluoromethyl)-6-bromoimidazo[l,2-<3]pyrimidine-3-carboxylate in 44 and 8% yields, respectively (97JCS(P1)981). Reactions in the presence of K2CO3 in MeCN at 90°C for 60h afforded only imidazo[l,2-a]pyrimidine-3-carboxylates. 

Reaction of 2-aminopyridine with dimethyl 2-methylmalonate in the presence of some drops of cone. HCl at 150°C for 1 h (96EUP733633), and with diethyl 2-(l-decyl)malonate at 120 °C for 5 min (94JCR(S)206) gave 2-hydroxy-3-methyl- and 2-hydroxy-3-(l-decyl)-4F7-pyrido[l,2-<3]pyrimidin-4-ones in 2.2% and 7.5% yields, respectively. Reaction of 3-benzyl-2-aminopyridine and diethylmalonate at 190-200 °C for 4 h yielded 9-benzyl-2-hydroxy-4i/-pyrido[l,2-<3]pyrimidin-4-one (01MIP9). Cyclocondensation... 

PPA and AcOH at 100 °C for 4 h gave 9-hydroxy-2,3-dimethyl-4 -pyrido-[l,2-<2]pyrimidin-4-one in 24% yield (96EUP733633). Reaction of 2-aminopyridine and ethyl 2-acetoxyacetoacetate in boiling EtOH gave 2-methyl-3-hydroxy-47/-pyrido[l,2-<3]pyrimidin-4-one in 47% yield (94KEZ(10)23). 

Oxo-47 -pyrido[ 1,2- jf]pyrimidin-2-yl]oxymethylsaccharin derivatives 418 exhibited human leukocyta elastase inhibitory activities (94EUP626378, 95USP5378720). 2-Substituted 4i/-pyrido[l,2-a]pyrimidin-4-one (419) is a potent human leukocyta elastase inhibitors Ki 1.79 yu-M) (96USP5512576). The 4i/-pyrido[l,2-<3]pyrimidin-4-one moiety was included in leukotriene antagonist 2-ethynylthiazole derivatives (98JAP(K) 98/195063)... 

PROTHYCIL PROTHYRAN PROTIURAL PTU (thyreostatic) T72 2-THIO-4-OXO-6-PROPYL-1.3-PYRIMIDINE 2-THIO-6-PROPYL-1.3-PYRIMIDIN-4-ONE 6-THIO-4-PROPYLURACIL THIURAGYL THYREOSTATII... 

THIO-6-PROPYL-l,3-PYRIMIDIN-4-ONE see PNXOOO 6-THIO-4-PROPYLURACIL see PNXOOO P-THIOPSEUDOUREA see ISROOO 6-THIOPURINE RIBONUCLEOSIDE see MCQ500 6-THIOPURINE RIBOSIDE see MCQ500... 

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