Pyrimidine is an aromatic heterocyclic organic compound similar to pyridine. One of the three diazines, it has the nitrogen atoms at positions 3 in the ring; the other diazines are pyridazine. In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine and uracil; the pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives, including the nucleotides cytosine and uracil, thiamine and alloxan. It is found in many synthetic compounds such as barbiturates and the HIV drug, zidovudine. Although pyrimidine derivatives such as uric acid and alloxan were known in the early 19th century, a laboratory synthesis of a pyrimidine was not carried out until 1879, when Grimaux reported the preparation of barbituric acid from urea and malonic acid in the presence of phosphorus oxychloride; the systematic study of pyrimidines began in 1884 with Pinner, who synthesized derivatives by condensing ethyl acetoacetate with amidines. Pinner first proposed the name “pyrimidin” in 1885.
The parent compound was first prepared by Gabriel and Colman in 1900, by conversion of barbituric acid to 2,4,6-trichloropyrimidine followed by reduction using zinc dust in hot water. The nomenclature of pyrimidines is straightforward. However, like other heterocyclics, tautomeric hydroxyl groups yield complications since they exist in the cyclic amide form. For example, 2-hydroxypyrimidine is more properly named 2-pyrimidone. A partial list of trivial names of various pyrimidines exists. Physical properties are shown in the data box. A more extensive discussion, including spectra, can be found in al.. Per the classification by Albert six-membered heterocycles can be described as π-deficient. Substitution by electronegative groups or additional nitrogen atoms in the ring increase the π-deficiency; these effects decrease the basicity. Like pyridines, in pyrimidines the π-electron density is decreased to an greater extent. Therefore, electrophilic aromatic substitution is more difficult while nucleophilic aromatic substitution is facilitated.
An example of the last reaction type is the displacement of the amino group in 2-aminopyrimidine by chlorine and its reverse. Electron lone pair availability is decreased compared to pyridine. Compared to pyridine, N-alkylation and N-oxidation are more difficult; the pKa value for protonated pyrimidine is 1.23 compared to 5.30 for pyridine. Protonation and other electrophilic additions will occur at only one nitrogen due to further deactivation by the second nitrogen; the 2-, 4-, 6- positions on the pyrimidine ring are electron deficient analogous to those in pyridine and nitro- and dinitrobenzene. The 5-position is less electron substituents there are quite stable. However, electrophilic substitution is facile at the 5-position, including nitration and halogenation. Reduction in resonance stabilization of pyrimidines may lead to addition and ring cleavage reactions rather than substitutions. One such manifestation is observed in the Dimroth rearrangement. Pyrimidine is found in meteorites, but scientists still do not know its origin.
Pyrimidine photolytically decomposes into uracil under ultraviolet light. As is the case with parent heterocyclic ring systems, the synthesis of pyrimidine is not that common and is performed by removing functional groups from derivatives. Primary syntheses in quantity involving formamide have been reported; as a class, pyrimidines are synthesized by the principal synthesis involving cyclization of β-dicarbonyl compounds with N–C–N compounds. Reaction of the former with amidines to give 2-substituted pyrimidines, with urea to give 2-pyrimidinones, guanidines to give 2-aminopyrimidines are typical. Pyrimidines can be prepared via the Biginelli reaction. Many other methods rely on condensation of carbonyls with diamines for instance the synthesis of 2-thio-6-methyluracil from thiourea and ethyl acetoacetate or the synthesis of 4-methylpyrimidine with 4,4-dimethoxy-2-butanone and formamide. A novel method is by reaction of N-vinyl and N-aryl amides with carbonitriles under electrophilic activation of the amide with 2-chloro-pyridine and trifluoromethanesulfonic anhydride: Because of the decreased basicity compared to pyridine, electrophilic substitution of pyrimidine is less facile.
Protonation or alkylation takes place at only one of the ring nitrogen atoms. Mono-N-oxidation occurs by reaction with peracids. Electrophilic C-substitution of pyrimidine occurs at the least electron-deficient. Nitration, azo coupling, sulfonation, hydroxymethylation, aminomethylation have been observed with substituted pyrimidines. Nucleophilic C-substitution should be facilitated at the 2-, 4-, 6-positions but there are only a few examples. Amination and hydroxylation has been observed for substituted pyrimidines. Reactions with Grignard or alkyllithium reagents yield 4-alkyl- or 4-aryl pyrimidine after aromatization. Free radical attack has been observed for pyrimidine and photochemical reactions have been observed for substituted pyrimidines. Pyrimidine can be hydrogenated to give tetrahydropyrimidine. Three nucleobases found in nucleic acids, cytosine and uracil, are pyrimidine derivatives: In DNA and RNA, these bases form hydrogen bonds with their complementary purines. Thus, in DNA, the purines adenine and guanine pair up with the pyrimidines thymine and cytosine, respectively.
In RNA, the complement of adenine is uracil instead of thymine, so the pairs that form a
Xanthorrhoea media, known as a Grass Tree, or Gulgadya in the Cadigal language, is a mid-sized plant in the genus Xanthorrhoea. The specific epithet media is from the Latin, refers to the fact that this species is in the middle of the taxonomic range for this group; this perennial shrub is found in eucalyptus forest on sandstone. It occurs most in dry sites such as exposed ridges and the sides of hills; the distribution is from near Sydney to the Blue Mountains. This plant has no trunk, or only a small trunk about 30 cm high, under the skirt of leaves, it may grow to 2.5 metres tall. The leaves are a mid to dark green, but not glaucous. Flowering occurs between March, dependent on fire; this species first appeared in the scientific literature in 1810, in the Prodromus Florae Novae Hollandiae, authored by the prolific Scottish botanist, Robert Brown
Swords and Sorcery is a fantasy role playing video game developed and published by Personal Software Services. It was released in the United Kingdom for the ZX Spectrum in 1985 and the Amstrad CPC in 1986; the game contains elements of dungeon crawling and revolves around a customisable player-character navigating through catacombs in order to secure a large wealth of treasure, whilst collecting seven pieces of sacred armour. The game was released with dedicated t-shirts and posters, it suffered from several delays throughout 1985 due to the complexity of programming. Swords and Sorcery received positive reviews from critics upon release, it won the "Game of the Month" award from Computer and Video Games in January 1986. Swords and Sorcery is presented in a first person top-down perspective and contains elements of dungeon crawling, a common trait of role playing video games; the game is set in a fictional land called Zob, in which he main objective is to explore its catacombs and discover a large wealth of treasure, alongside collecting seven pieces of sacred Zob armour.
The game begins with allowing the player to choose their player-character. Once a character has been created, a 14 in-game day training scheme will commence which gives the player an opportunity to improve their abilities such as lock picking, sword fighting and thieving. An in-game armoury is accessible at any time, which includes utilities such as body armour and various weaponry; the form of currency in the game is dragon's teeth, which can be used to purchase items and equipment. Movement through the catacombs is controlled by command inputs and keywords, referred to in-game as MIDAS. For example, entering in the word "hit" will bring down a menu which will display various forms of attacking techniques; the left side of the screen displays an animated first person perspective of the respective tunnel or room the player is in, whereas the right side of the interface displays a general top-down view of the catacombs. The bottom of the screen features a command box and announces available options or hints to the player.
During the game, enemies such as gargoyles and warriors will appear at random and attack the player if confronted. Magic spells such as poison and fire are able to defeat enemies, alongside weaponry such as swords and axes; the player-character has both a health and magic bar, which will deplete once attacked by an enemy or by using magic spells, respectively. Items in the game include treasure and artefacts which may have a chance of giving the player negative effects, such as draining life and paralysing movement. Personal Software Services was founded in Coventry, England, by Gary Mays and Richard Cockayne in November 1981; the company was known for creating games that revolved around historic war battles and conflicts, such as Theatre Europe and Falklands'82. The company had a partnership with French video game developer ERE Informatique, published localised versions of their products to the United Kingdom; the Strategic Wargames series was conceptualised by software designer Alan Steel in 1984.
During development of these titles, Steel would research the topic of the upcoming game and pass on the findings to other associates in Coventry and London. Some games of the series were met with controversy such as Theatre Europe. In 1983, the company received recognition for being "one of the top software houses" in the United Kingdom, was a finalist for BBC Radio 4's New Business Enterprise Award for that year. In 1986, Cockayne took a decision to alter their products for release on 16-bit consoles, as he found that smaller 8-bit consoles, such as the ZX Spectrum, lacked the processing power for larger strategy games; the decision was falsely interpreted as "pulling out" from the Spectrum market by video game journalist Phillipa Irving. Following years of successful sales throughout the mid 1980s, Personal Software Services experienced financial difficulties, in what Cockayne admitted in a retrospective interview that "he took his eye off the ball"; the company was acquired by Mirrorsoft in February 1987, was dispossessed by the company due to strains of debt.
The game was delayed several times for over a year. Before its announcement and Sorcery had been in development from nearly two years prior to 1985. PSS explained the delays as due to game's complexity; the game was PSS's biggest launch to date. Upon release and Sorcery came with t-shirts and posters; the game received positive reviews upon release. Rachael Smith of Your Sinclair praised the imaginative atmosphere the game offered, stating that developers drew the players into a "convincing world" and speculated that the game would become a "cult of sorts". Philippa Irving of Crash praised the presentation as "super" and the graphics as "rare for this type of game", adding that it offered "brilliant" animation which shows the detail in the "best way possible". Gary Rook of Sinclair User opinionated that Swords and Sorcery was aimed at "Rambo-style" dungeon explorers. Regarding the graphics, Rook stated that they were "not staggering", but felt that they served a purpose and would have been "deadly dull" if the game was text-based only.
General elections were held in the Cook Islands on 7 September 2004. Initial results showed the Democratic Party winning by a wide margin, but close results led to 11 electoral petitions being filed, delaying the date Parliament could sit until mid-December. In the interim, Prime Minister Robert Woonton announced that he was forming a coalition government with the rival Cook Islands Party; this led to a split within the Democrats, with Woonton and four other MPs leaving to form the Demo Tumu Party. With 14 MPs, the coalition had a comfortable majority in Parliament; the results of the electoral petitions saw the seat of Titikaveka change hands while Woonton's seat was a dead tie. Woonton subsequently resigned in order to fight a by-election, causing his government to be dissolved, he was succeeded by Jim Marurai. Cook Islands General Election 2004 Preliminary Results
Dyer State Wayside, a rest stop with picnic tables and public toilets, lies about 10 miles south of Condon, along Oregon Route 19. It occupies 0.6 acres in a narrow canyon along a branch of Thirty Mile Creek at the mouth of Ramsey Canyon. The grounds are named for J. W. Dyer, who gave the land to the state in 1931. In 1997, a group of volunteers called Dyer Partners renovated the park, which had become "an overgrown weed patch with rotting picnic tables", they trimmed locust trees, built fences, repaired picnic tables, planted fruit trees. The federal Bureau of Land Management donated two surplus toilets in 1999 and the Oregon Parks and Recreation Department built vaults for the toilets. In 2000, OPRD installed an irrigation system and Gilliam County road crews made pathways and improved the parking lot. In 2004, the group, whose numbers were said to be "dwindling," made another stab at improving the site. With assistance from personal from Deschutes State Park, they aimed to make connections with water pipes installed two years earlier.
As of 2016, the park's sole textual reference on the Oregon State Park's website was as a place where metal detecting can be pursued
Michael Warren is an Australian rules footballer who plays for Claremont in the West Australian Football League and once played for Fremantle in the Australian Football League. He plays as key defender. Warren from South Bunbury, made his debut for Claremont in 2003, he was selected by Fremantle with the 41st selection in the 2004 Rookie Draft and was elevated to the senior list at the end of the 2005 AFL season. He made his AFL debut against Melbourne at the MCG in Round 7, 2006 when injuries forced first-choice ruckmen Aaron Sandilands and Justin Longmuir to miss the game, he was delisted by Fremantle at the end of the 2006 AFL season without playing another game but continued to play for Claremont in the WAFL. He was a member of Claremont's 2004, 2005 and 2007 WAFL Grand Final teams, but lost all three, twice to Subiaco and once to South Fremantle, he switched to play for East Fremantle in 2010. Michael Warren's playing statistics from AFL Tables Michael Warren WAFL Player Profile