You can safely canned dice tomatoes but they might not stay diced when canned.  Commercially they have different processes than we have tested for home food preservation.  I would suggest using the Crushed hot pack tomatoes found on Page 11 in PNW Canning Tomatoes and Tomato Products.   https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/pnw300.pdf   You cook aproximately 1/6 of the volume of the tomatoes you plan to can first and then add the remaining diced tomatoes and simmer for 5 minutes, then put into jars hot and process for the 35 for pints, 45 for quarts. 
 
You could dice all your tomatoes and let them sit for a little while and drain off the juice.  If you have about 1/6 of the volume you plan to can in drained liquid, you could heat that to boiling, add rest of diced tomatoes, bring to a boil and simmer 5 minutes.  Then put in jars, adding 1T bottle lemon juice for pints. 2 T. per quart of lemon juice. 

Hope that helps,  If you have other questions you might like to call the OSU Food Preservation Hotline open M-F from 9 am-4pm.  Certified Master Food Preserver volunteers are available to answer your calls.  The number is <personal data hidden>.  

Thanks for using Ask Extension

Nellie Oehler

Thank you very much! 

On Fri, Sep 16, 2022 at 5:32 PM, Ask Extension

<<personal data hidden>> wrote:

You are welcome

Nellie