Let $q \geq 5$ be a prime number, and consider : $N_q = \displaystyle{\small \prod_{\substack{p \leq q \\ \text{p prime}}} {\normalsize p}}$
Using Chinese remainder theorem we can show that :
$$\#\{(b,b+2) \in \mathbb{N}^2 \, | \, b+2 \leq N_q \text{ and } \gcd(b,N_q)=\gcd(b+2,N_q)=1\} = \displaystyle{\small \prod_{\substack{p \leq q \\ \text{p prime}}} {\normalsize (p-2)}}-1$$
Let $r$ be the next prime to $q$.
We have : $\gcd(n, N_q) = 1 \text{ and } q < n < r^2 \implies n \in \mathbb{P}$
Then if we prove that for every $q$ the region $q+1,q+2,\cdots,r^2-1$ has at least a tuple $(b,b+2)$ coprime to $N_q$ we prove the twin prime conjecture.
My question is : has this region been studied before ? and what are the most important results found about it?