Am I eligible for a 144 hours transit visa to Beijing

My flight is composed from two different tickets.

1. Ticket one is from Singapore to Beijing with Singapore Airlines.
My pland is to stay 4 days in Beijing.

2. Ticket two is from Beijing to Los Angeles on China airlines.

Am I eligible for the 144 transit visa although I am using to seperate air tickets?

Thank you in advance for you assistance.

Ivo