2,4-Dimethyl-6-hydroxypyrimidine

The reaction of W2(dmhp)4 (dmhp = the anion of 2,4-dimethyl-6-hydroxypyrimidine) with the lithium salt of N, JV -diphenylacctamidine, Li(PhN)2CMe, yields a red crystalline air sensitive but thermally stable product.97 It crystallizes in space group jP2,/b with Z = 2, requiring the molecules to lie on crystallographic inversion centres. The W W distance, 2.174(1) A, is very similar to that in W2(dmph)4. 

Carboxylate-bridged Cr dimers are synthesized from chromocene. Benzoic acid, pivalic acid, and 9-anthracenecarboxylic acid react with (f/ -CsH5)2Cr to form Cr2(02CR)4 dimers. Chromium hexacarbonyl is oxidized to dimeric Cr(II) complexes by 2,4-dimethyl-6-hydroxypyrimidine and A, A -(3,5-xylyl) formamidine in refluxing... 

Amidines react with P-keto esters to provide hydroxypyrimidines. The synthesis of the 2,6-dimethyl-4-hydroxylpyrimidine (9) has been improved dramatically by combining Pinner s procedure with that of Donleavy et al. for the synthesis of 6-methyluracil. 

Pyrazino[l,2-z]pyrimidine-6,8-dionc was prepared from [3+3] atom fragments by reacting 6-hydroxypyrimidine-4-carboxylic acid with 2-aminoacetaldehyde dimethyl acetal <2005W02005/016927>. 

The deoxyuracil derivatives-2-hydroxypyrimidine (69) (2-pymoH), 4-hydroxy-pyrimidine (70) (4-pymoH), 4,6-dimethyl-2-hydroxypyrimidine (71) (2-dmpymoH), and pyrimidine (72) (pym), shown here as the minor tautomer, have provided metallacalixarenes having closer resemblance to classical calixarenes, as compared with those obtained from uracil. The reactions of [(en)M(H20)2KN03)2 (M = Pd and Pt ) with 2-pymoH in water gave tetranuclear metallacalixarenes [(en)Pd(2-pymo-N2 N3)]4(N03)4 (73) and [ en)Ft 2-pjmo-Nl N3MN03)2 (74) (2000IC2301). As compared with uracil-based systems, the appearance of one set of resonances for each of pyrimidine PI, in their IT NMR spectra showed fast... 

Dimethyl-2-hydroxypyrimidine [108-79-2] M 124.1, m 198-199°. Crystd from absolute EtOH (charcoal). 

A Princeton group announced the first synthesis of L-5-deazaFA (91) via a path which to date remains the shortest and most direct route to this series [79, 80], In one step, reaction of 2,4-diamino-6-hydroxypyrimidine (87a) with purified triformylmethane [81a,b] produced 2-amino-5-deazapterin-6-carbox-aldehyde (88a), which was characterized as the acetamide (89a). Reaction of (89a) with dimethyl p-aminobenzoyl-L-glutamate in glacial HOAc afforded an intermediate imine which was reduced in situ with borane-triethylamine, yielding (90). Saponification of the amide and esters then completed the synthesis of (91) in 62% yield from (88a) (Scheme 3.18). Adaptation of this... 

Figure 5. (a) Emission spectra (A.exc = 436 nm) of Mo2(dmhp)4 (dmhp = 4,6-dimethyl-2-hydroxypyrimidine) in (o) methanol, and HCl-acidified methanol with (i) 1-, (ii) 2-, (iii) 3-, and (iv) 4-equivalents of HC1 per equivalent of metal complex, (b) Emission spectra (Xexc = 436 nm) of (v) terf-octylamine-intercalated zirconium phosphate and (vi) ethanolic preswelled zirconium phosphate treated with Mo2(dmhp>4. Traces (o) - (v) show relative emission intensities and traces (v) and (vi) are arbritrary and unrelated to each other. 

Adenine-HCl H20 4,6-Dimethyl-2-hydroxypyrimidine Phloroglutinol diammoniate l,3j5-Triaminocyclohexane 2H2O... 

Diaminopyrimidines or l-aminopyrimidine-2-thiones were found to be suitable molecular fragments for the synthesis of heterocycles. Thus, l,6-diamino-2-oxo-4-hydroxypyrimidine (65) underwent cyclocondensation with dimethyl oxalate yielding 8-hydroxy-277,3/f,6/f-pyrimido[l,6-i)][l,2,4]triazine-2,3,6-trione (66) (Equation (12)) <85JHC1317>. Similarly, the reactions of the 2-thione (67) with haloketones gave pyrimido[2,l-fe][l,2,4]thiadiazines (68) (Equation (13)) <71IJC404>. 

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