Write the reaction equation: Methane-chloromethane-butane-dichlorobutane-cyclobutane

Let’s implement the solution of the transformation chain for organic substances:
CH4 + Cl2 = CH3Cl + HCl – substitutions, methane chloride was obtained;
2CH3Cl + 2Na + 2CH3Cl = C4H10 + 2NaCl – butane is released during the Würz reaction;
C4H10 + 2Cl2 = C4H8Cl2 + 2HCl – dichlorobutane was formed during the substitution reaction;
С4Н8Cl2 + 2Na = C4H8 + 2NaCl – cyclobutane was obtained.
The solution shows the relationship of hydrocarbons: saturated, cyclic on the example of methane, cyclobutane. The reaction products are of practical importance, for example, chloromethane, dichlorobutane as solvents.