Word "preclude"

[Bassim]

I have tried to use "preclude" in my sentences. Would you please correct my mistakes?

1.The president tried to preclude inquiry into his contacts with a foreign secret service.

2. The large company is trying to preclude its smaller rivals to get into its market.

 

[GoesStation]

Number 1 is just barely acceptable. Number 2 doesn't work at all.

 

[Bassim]

Would my second sentence be better like this:

The large company is trying to prevent its smaller rivals to get into its market.

 

[GoesStation]

You prevent someone from getting into a market.

 

[Tdol]

The president could try to block/stymie such inquiries.