Stir together vinegar, ketchup, brown sugar, Worcestershire sauce, Dijon mustard, garlic, 1/2 teaspoon salt, and 1/2 teaspoon black pepper in a saucepan over medium-low heat; simmer sauce for 20 minutes. Remove from heat and allow to sit for 5 minutes.

Preheat an outdoor grill for medium heat and lightly oil the grate.

Season pork chops with salt and pepper. Pour a small amount of sauce from the saucepan into a bowl. Brush chops with sauce from the bowl. Discard any remaining sauce from the bowl.

Cook pork chops on the preheated grill until no longer pink in the center, about 5 minutes per side. An instant-read thermometer inserted into the center should read 145 degrees F (63 degrees C). Allow pork chops to rest for 3 minutes. Serve with remaining sauce on the side.