Methylcholanthrene is a highly carcinogenic polycyclic aromatic hydrocarbon produced by burning organic compounds at very high temperatures. Methylcholanthrene is also known as 3-methylcholanthrene, 20-methylcholanthrene or the IUPAC name 3-methyl-1,2-dyhydrobenzo[j]aceanthrylene. The short notation often used is 3-MC or MCA. This compound forms pale yellow solid crystals when crystallized from benzene and ether. It has a melting point around 180 °C and its boiling point is around 280 °C at a pressure of 80 mmHg. Methylcholanthrene is used in laboratory studies of chemical carcinogenesis. It is an alkylated derivative of benz[a]anthracene and has a similar UV spectrum. The most common isomer is 3-methylcholanthrene, although the methyl group can occur in other places. 3-Methylcholanthrene, a known carcinogen which builds up in the prostate due to cholesterol breakdown, is implicated in prostate cancer. It "readily produces" primary sarcomas in mice. History In 1933, the first article about methylcholanthrene was published. Here they described the synthesis of the compound. Not many years later, it became clear that this compound had toxic properties to humans and animals. Therefore, a lot of interest was shown in the compound and it was used often in toxicological research. Methylcholanthrene is often tested on mice and rats to derive information for cancer medicine development. Due to the influence of the compound on the central nervous system, its responses and change in response are compared. It is also known that due to genetic mutations, the compound causes cancer cells to develop. In 1982, the last article appeared on the synthesis of methylcholanthrene. The yield of 93% was reached and therefore no further adjustments were made to the synthesis scheme. Synthesis First 3-MC was synthesized with the method of reference. Later the synthesis of the compound was improved. The synthesis of 3-MC consists of a few steps, visualized in figure 1; the first step is the key to success for the synthesis. 4-methylindanone (1) reacts in condensation with lithium salt of N,N-diethyl-1-naphthamide (2). At -60 ̊C the reaction of 1 and 2 afforded evenly to the lactone (3), the carbonyl addition product which underwent conversion on treatment with acid. The free acid (4) was obtained when the latter was cleaved reductively with zinc and alkali. Cyclization of the product occurred when treated with ZnCl2 in acetic acid anhydride and gave the compound 6-acetoxy-3-MC (5). Reducing this product with hydriodic acid in propionic acid resulted in 3-MC. Mechanism 3-MC has an inhibitory function