You can add a new variable in Reduce do get your multiplication, just like this

In[13]:= Reduce[ ans == x y && x*y > 50 && x*y < 100 && x < 100 && x > 1 && y > 1 && y < 50, ans, {x, y}, Integers] Out[13]= ans == 51 || ans == 52 || ans == 54 || ans == 55 || ans == 56 || ans == 57 || ans == 58 || ans == 60 || ans == 62 || ans == 63 || ans == 64 || ans == 65 || ans == 66 || ans == 68 || ans == 69 || ans == 70 || ans == 72 || ans == 74 || ans == 75 || ans == 76 || ans == 77 || ans == 78 || ans == 80 || ans == 81 || ans == 82 || ans == 84 || ans == 85 || ans == 86 || ans == 87 || ans == 88 || ans == 90 || ans == 91 || ans == 92 || ans == 93 || ans == 94 || ans == 95 || ans == 96 || ans == 98 || ans == 99 

This is an undocumented usage of Reduce, which can eliminate some variables in the equations.

EDIT

Using to rules will be better:

x y/.{ToRules@Reduce[x*y > 50 && x*y < 100 && x < 100 && x > 1 && y > 1 && y < 50, {x, y}, Integers]} 

@Michael thanks!

in your situation, the result will be in the form x==2&&y==26||x==2&&y==27...... so we can use replacement rules to make it into {{x->2,y->26},{x->2,y->27},......} Then let ReplaceAll do the job.

The code is as follows:

x y /. (Reduce[x*y > 50 && x*y < 100 && x < 100 && x > 1 && y > 1 && y < 50, {x, y}, Integers] /. {Equal -> Rule, And -> List, Or -> List})