Synthesis of boron-substituted pyrimidines and borazaroquinazolines

Abstract

Two approaches to the synthesis of boron-substituted pyrimidines and borazaroquinazolines (1) have been explored First, (dibutoxyboryl)ethene and bromomalononitrile were converted to l,l-dicyano-3-bromo-3-(dibutoxyboryl)propane (2), which was reduced with triphenyltin hydride to l,l-dicyano-3-(dibutoxyboryl)propane (3), which condensed with thiourea to yield 2-mercapto-4,6-diamino-5-(2-dihydroxyborylethyl)pyrimidine (4a). However, conversion of 4a to a borazaroquinazoline was not attempted because the development of boron-substituted carbanion chemistry promised a more direct and efficient approach. This second method involved condensation of 4,6-dichloro-5-formylpyrimidine (5) with the carbanion from tetrakis(trimethylenedioxyboryl)methane to form 4,6-dichloro-5-[2,2-bis(trimethylenedioxyboryl)vinyl]pyrimidine (6a), which on treatment with ammonia at 25 °C yielded 4-chloro-6-trimethylenedioxyboryl-7-hydroxy-7,8-dihydro-7,8-borazaroquinazoline (7a), which reacted with ammonia at 75 °C to form the 4-amino derivative 8. Improved yields were obtained in a similar sequence starting from tetrakis(ethylenedioxyboryl)methane. Characterization of the amino-substituted borazaroquinazolines was aided by 13 *C NMR correlations.Substitution of a boron atom for a carbon in a biochemically significant molecule might lead to antimetabolite ac-

Synthesis and in vitro evaluation of boronated uridine and glucose derivatives for boron neutron capture therapy.

“…4a: yield 770 mg (93%) of white crystals; mp 136-137 °C; MS (FAB+, 3-NBA) 401 ( + H)+; -NMR (CD3OD) 1.30-3.00 (br m, 10 , B-H), 3.74 (a) 3.89 (b) (d of AB q, 2 H, H2-5', JMW = 12.46, J4'5a' = 2.83, J4-5a. = 2.36), 3.97-4.21 (m, 3 , H-2', H-3', H-4'), 4.20 (a) 4.27 (b) (AB q, 2 H, CH2Ccalboralle, J^= 11.3), 4.68 (br s, 1 H, C^g^H), 5.67 (d, 1 , H-5, J5,6 = 8.1), 5.84 (d, 1 H, H-V, Jr2 = 3.17), 8.05 (d, 1 H, H-6). Anal.…”

Borata‐Alkene Species as Nucleophilic Reservoir

“…Rathke and Kow [13a] reported next the condensation of the lithium borylmethide salt 2 with cyclohexanone to produce methylenecyclohexane 40 (Scheme 20b). Matteson and co‐workers expanded the general access to α‐mono‐ and α‐polyboryl carbanions and proved their reactivity through similar condensation sequences to those in Scheme 20 [57–63] …”

Synthesis and Antimicrobial Activity of 2-{4'-[(6"-Aryl)2"-Hydroxy-3",4"-Dihydro-Pyrimidine-4"-yl]-Phenyl Amino}-6-[Bis (2'"-Chloroethyl) Amino]-4-Methoxy-1,3,5-Triazine

“…Pyrimidine nucleus possess broad spectrum of pharmacological activities which are reflected by their use as analgesic 1 , anticonvulsant 2 , antimicrobial [3][4] , antipyratics 5 , antiinflammatory 6 , antitumor 7 , antineoplastic 8 , antimalarial 9 , antithyroid 10 , anthelmintic 11 , Anti-HIV [12][13] , antiviral 14 , antagonists [15][16][17] etc. With a view to getting of synthesis pyrimidine derivatives.…”