Hi @Savelec
the LPC1768 is a replacement for the LPC2368.
Regarding to the pin, LPC1768 pin13 is nc while LPC2368 connects to Vdd. The LPC1768 and the LPC2368 are not strictly pin-compatible. However it's possible to directly replace a LPC2368 with an LPC1768/66 (at the same board.).In this case it's no problem to connect the NC pin 13 of the LPC1768 to Vdd
However, please note the longevity of LPC1766/8/9 are less than 5 years left. We don’t have other pin to pin replacement longer than10 years.
Hope this helps.
Jun Zhang